Three-dimensional Plate Research Articles

Augmented reality and three-dimensional plate library-assisted posterior minimally invasive surgery for scapula fracture.

Treating scapular fractures is still a challenging task for surgeons. We aimed to evaluate the feasibility, accuracy, and effectiveness of augmented reality (AR) and three-dimensional (3D) plate library-assisted posterior minimally invasive surgery, named AR-scapular system for scapula fracture. We speculated that using AR-scapular system would improve efficiency and quality for scapular fracture surgery. We retrospectively reviewed the records of 21 patients with scapular fractures treated by posterior minimally invasive surgery with reconstruction plates: nine patients were treated with conventional fixation in group I; whereas 12 patients were treated with pre-operative virtual simulation and intra-operative navigation-assisted fixation using AR-scapular system. We compared operative time, blood loss, complication, and Hardegger function between two groups. Statistical analyses evaluated significant differences between the groups for each of these variables. In group II, the pre-operative virtual simulation time was 44.42 ± 15.54min. The time required for pre-operative contouring of the plates was 16.08 ± 5.09 minutes. The patients in group II had significantly shorter operation time and less blood loss (- 28.75min and - 81.94ml, respectively; P < 0.05) than patients in the conventional surgery group. The average numbers of plates used were 1.56 ± 0.53 in group I and 1.25 ± 0.45 in group II. The difference was not statistically significant (P > 0.05). The follow-up function outcome results were similar between groups (P > 0.05). There were no intra-operative or post-operative complications for all patients. Augmented reality and 3D plate library-assisted posterior minimally invasive surgery is an effective and reliable method for treating scapular fractures which can provide precise pre-operative planning and intraoperative navigation. This time-saving approach can give a more customized treatment plan, allowing for a safer reduction surgery. What is more, the portable projector is cheap and easy to use.

Characteristics of Trunk Compensation Movements during Walking in People with Bilateral Transtibial Amputation: A Cross-sectional Study

ABSTRACTObjectives:The gait characteristics of people with bilateral transtibial amputation are not well understood. This study aimed to clarify changes in trunk lateral bending and the trunk flexion angle during walking in people with bilateral transtibial amputation.Methods:In this cross-sectional study, four participants with bilateral transtibial amputation who could walk without assistance (BTTA group) and ten able-bodied participants (control group) were recruited. The range of motion of trunk lateral bending, the trunk flexion angle, and other gait parameters during comfortable-speed and maximum-speed walking were measured using a three-dimensional motion analysis system and force plates. These parameters were compared between the amputees and the controls.Results:During maximum-speed walking, the BTTA group walked slower with a smaller trunk flexion angle (median, 1.75° vs. 4.79°, P=0.036) and greater double leg support time (0.18 vs. 0.12, P=0.008) when compared with the control group. The other parameters during maximum-speed walking were not significantly different between the two groups. During comfortable-speed walking, none of the parameters were significantly different between the two groups.Conclusions:Compensatory trunk flexion angle decreases markedly during maximum-speed walking in people with bilateral transtibial amputation. People with bilateral transtibial amputation may be changing the trunk flexion angle to walk faster. When evaluating gait compensation for people with bilateral transtibial amputation, trunk flexion angle may be an important index and maximum-speed walking is needed to detect the change in trunk flexion angle.

Non-extraction camouflage treatment using extra-alveolar skeletal anchorage

Abstract A 23-year-old female patient with moderate crowding and a bilateral molar scissor-bite was successfully treated without tooth extraction. Extra-alveolar skeletal anchorage, involving a three-dimensional key plate in the maxilla and two miniscrews in the buccal shelf of the mandible, were used for distalisation, buccolingual uprighting, and the intrusion of molars by fixed orthodontic appliances. Cone-beam computed tomography was used to identify available posterior space for the distalisation and buccolingual correction of the molars in scissor-bite. The total treatment time was 24 months. Post-treatment results showed good occlusal relationships and smile aesthetics. Twelve-month post-treatment records demonstrated no significant relapse and a favourable facial balance.

Three-dimensional inlay-guided endodontics applied in variant root canals: A case report and review of literature

BACKGROUNDRoot canal retreatment is common after root canal therapy in clinical situations. Especially, completing the retreatment of variant root canals can be challenging. This is particularly true for the molars located at the end of the dental arch. However, advancements in digital dental diagnosis and treatment techniques can solve these problems. Here, we describe a case of a maxillary second molar with a variant distobuccal root canal treated via a novel “inlay-guided endodontics” technique based on improved computer-generated programs. CASE SUMMARYA 63-year-old man complained of a defect in the maxillary left second molar. The tooth, diagnosed with post-treatment endodontic disease, was initially treated by conventional methods, which were ineffective. Our “inlay-guided endodontics” technique was subsequently adopted, with the establishment of a precise integrated three-dimensional (3D) plate model of cone-beam computed tomography data and a digital impression of the dentition. An optimal root canal approach was generated for the “virtual file” in the 3D model. The plate data were imported into a 3D printer and printed. With the help of the guide plate, the file was accurately placed into the cervical third of the distal root canal. The root canal and prosthodontic treatments successfully proceeded subsequently. CONCLUSIONOur newly developed inlay guide plates may facilitate individualized and minimally invasive root canal treatment.

The performance tests of three-dimensional printing titanium alloy craniomaxillofacial bone plate: A preliminary preclinical study

Background/purposeBecause of the complex anatomical structure of the maxillofacial skeleton, bending plates is necessary during surgery. The fast developing three-dimensional printing (3DP) technology has provided a new method for making personalized craniomaxillofacial bone plates. However, the properties of these bone plates remain unknown. This study evaluates the mechanical, fatigue, and morphological properties of these bone plates, which may provide data supporting future clinical applications. Materials and methodsThe 3DP bone plate was fabricated by selective laser melting (SLM) and electron beam melting (EBM) technologies. Mechanical, surface, and defect analyses were performed to compare their properties with a standard machined sample. One-way analysis of variance was applied, with p < 0.05 considered significant. ResultsThe 3DP craniomaxillofacial bone plate had better bending strength than that of the standard machined plate (p < 0.01). Whereas the fatigue resistance of the 3DP bone plate needs to be improved in the future. Surface analysis indicated greater roughness of the 3DP bone plate (p < 0.01). However, the surface roughness could be significantly reduced by polishing the surface, which would meet the needs of clinical application after polishing. Further defect analysis revealed the internal defect inside the plate, which should be avoided to improve the mechanical strength of the printed sample in the future. ConclusionThe 3DP titanium craniomaxillofacial bone plate has good mechanical performance and surface morphology, meeting the requirements of clinical application. However, poorer fatigue resistance and a high number of internal defects should be modified in the future.

Earlier detection facilitates skilled responses to deceptive actions.

High-skilled and recreational rugby players were placed in a semi-immersive CAREN Lab environment to examine susceptibility to, and detection of, deception. To achieve this, a broad window of seven occlusion times was used in which participants responded to life-size video clips of an opposing player 'cutting' left or right, with or without a deceptive sidestep. Participants made full-body responses to 'intercept' the player and gave a verbal judgement of the opponent's final running direction. Response kinematic and kinetic data were recorded using three-dimensional motion capture cameras and force plates, respectively. Based on response accuracy, the results were separated into deception susceptibility and deception detection windows then signal detection analysis was used to calculate indices of discriminability between genuine and deceptive actions (d') and judgement bias (c). Analysis revealed that high-skilled and low-skilled players were similarly susceptible to deception; however, high-skilled players detected deception earlier in the action sequence, which enabled them to make more effective behavioural responses to deceptive actions.

Flow interaction of three-dimensional self-propelled flexible plates in tandem

Tandem configurations of two self-propelled flexible flappers of finite span are explored by means of numerical simulations. The same sinusoidal vertical motion is imposed on the leading edge of both flappers, but with a phase shift ( $\phi$ ). In addition, a vertical offset, $H$ , is prescribed between the flappers. The configurations that emerge are characterized in terms of their hydrodynamic performance and topology. The flappers reach a stable configuration with a constant mean propulsive speed and a mean equilibrium horizontal distance. Depending on $H$ and $\phi$ , two different tandem configurations are observed, namely compact and regular configurations. The performance of the upstream flapper (i.e. the leader) is virtually equal to the performance of an isolated flapper, except in the compact configuration, where the close interaction with the downstream flapper (i.e. the follower) results in higher power requirements and propulsive speed than an isolated flapper. Conversely, the follower's performance is significantly affected by the wake of the leader in both regular and compact configurations. The analysis of the flow shows that the follower's performance is influenced by the interaction with the vertical jet induced by the vortex rings shed by the leader. This interaction can be beneficial or detrimental for the follower's performance, depending on the alignment of the jet velocity with the follower's vertical motion. Finally, a qualitative prediction of the performance of a hypothetical follower is presented. The model is semi-empirical, and it uses the flow field of an isolated flapper.

Analysis of the Effect of Wearing Extensible and Non-Extensible Lumbar Belts on Biomechanical Factors of the Sit-to-Stand Movement and Pain-Related Psychological Factors Affecting Office Workers with Low Back Pain.

This study aimed to investigate the effects of wearing extensible and non-extensible lumbar belt (LB) on biomechanical factors of the sit-to-stand (STD) movement and pain-related psychological factors affecting office workers with low back pain. Among 30 office workers, 15 with low back pain (LBP) were assigned to the experimental group and 15 healthy adults were assigned to the control group. The participants performed STD movement in random order of three different conditions: without LB (Condition 1), with extensible LB (Condition 2), and with non-extensible LB (Condition 3). Biomechanical variables of STD movement in each condition were measured using a three-dimensional motion analysis system and force plate. Pain-related psychological factors were measured only in the experimental group. Among the biomechanical factors of STD movement, an interaction effect was found in the maximum anterior pelvic tilt angle and total-phase range of motion of the trunk (p < 0.05). Pain intensity, pain-related anxiety, and pain catastrophizing were decreased in the conditions with lumbar belts (Conditions 2 and 3) compared to the condition without LB (Condition 1) (p < 0.05). Extensible and non-extensible lumbar belts engender biomechanically beneficial effects during STD movement in both office workers with LBP and healthy office workers. Further, pain intensity, pain-related anxiety, and pain catastrophizing were decreased in office workers with LBP. Therefore, both types of extensible lumbar belts may be helpful in the daily life of patients with LBP and office workers.

Hard Tissue Preservation and Recovery in Minimally Invasive Alveolar Surgery Using Three-Dimensional Printing Guide Plate.

For completely impacted teeth, it is of great significance to locate teeth accurately, preserve hard tissue and recovering the height of alveolar ridge. This can be effectively solved by the digital three-dimensional printing guide technology. Ten patients with completely impacted tooth were selected in this experiment. After cone-beam computed tomography scan, the dicom formal computed tomography data was analyzed for threedimensional reconstruction by mimics 17.0 software. Then determining the surgical plan and making surgical guide plate. Threedimensional printing guide plate assisted piezosurgery was used to remove bone and extract impacted teeth. After that, the removed bone cap was back to the original position. Cone-beam computed tomography was used for each operated patients after 1 week and 6 months. The surgical guide plates can locate teeth accurately and the surgery time was reduced for all patients. A week later, all patients healed well and removed the stitches on time. Cone-beam computed tomography showed that the retention of bone caps was good and there was no displacement. All patients showed a normal parameter of pain. Six months later, cone-beam computed tomography showed good bone formation in the extraction area, which filled with new bones completely. The recovery of bone outline and height of alveolar crest at the surgical site were basically consistent with those before the operation. Three-dimensional printing guide plates combining with fenestration and bone-cap restoration can locate impacted teeth accurately, reduce the extraction volume of bone, shorten surgery time, and alleviate complications. This was conducive to preserve and restore hard tissue and had great prospective.

A comparison of plantarflexor musculotendon unit output between plyometric exercises and running

ObjectivesPlyometric exercises are used to prevent and rehabilitate plantarflexor running injuries. To facilitate exercise programming, this study compared plantarflexor musculotendon output during running to plyometric exercises. DesignExperimental study with cross-over. MethodsFourteen trained distance runners performed running, ankle bouncing, A-skips, bounding, and hurdle jumps. Three-dimensional motion capture and force plate data were collected and computational simulations used to calculate gastrocnemius lateralis and soleus musculotendon peak forces, strain, power generation and absorption, and total positive and negative work. Percentage difference and standardised mean differences were used to compare variables between plyometrics and running. Musculotendon units were classified as energy generators or absorbers according to their net mechanical work. ResultsBoth plantarflexors behaved as net energy generators during running. Plantarflexor peak force and power generation and absorption were lower in the A-skip and ankle bounce compared to running. Soleus behaved as a net energy absorber during hurdle jumps, with greater total negative work (16.5%; standardised mean difference 0.92) and higher peak strain (0.3%; standardised mean difference 0.28) during hurdle jumps than running. Gastrocnemius lateralis behaved as a net energy absorber during bounding, with greater total negative work (63.8%; standardised mean difference 0.81) and peak strain (0.4%; standardised mean difference 0.77) during bounding than running. ConclusionsThe ankle bounce and A-skip may be appropriate exercises when runners desire lower plantarflexor loads than running. Hurdle jumps elicited high soleus loads but low gastrocnemius lateralis loads, highlighting the disparate function of the plantarflexors. Bounding demanded high plantarflexor musculotendon output and may be suitable when eccentric overload is desired.

Relationships between hip strength and hip biomechanics during running in people with femoroacetabular impingement syndrome

Introduction: Femoroacetabular impingement (FAI) syndrome is a motion-related condition associated with an increased risk of hip osteoarthritis. As well as altered movement patterns, people with FAI syndrome have demonstrated lower hip strength compared to controls. Importantly, hip strength has been shown to relate to self-reported symptoms and therefore, hip strengthening is often a recommended non-surgical treatment strategy. The relationship between hip strength and running biomechanics has been examined in numerous cohorts, but not FAI syndrome. Therefore, the aim of this study was to explore the relationship between hip strength and hip biomechanics during running in FAI syndrome, and explore whether relationships were sex dependent. Methods: Biomechanics during running and hip strength were assessed in 42 participants (22 women and 20 men) aged 18-50 years with radiographically confirmed cam morphology. Hip biomechanics during the stance phase of running (3-3.5 m/s) were collected using three-dimensional motion capture and force plates. The hip strength of six muscle groups were assessed via hand-held dynamometry. Linear models were used to examine the relationship between strength (independent variable) and biomechanics (dependent variable), controlling for body mass and running velocity, with sex investigated as an interaction term (sex*strength). Results: There were no significant relationships between hip strength and hip biomechanics during running for five of the six muscle groups investigated. A significant negative relationship was observed between hip external rotation strength and hip frontal plane range of motion during running, independent of sex (p = 0.03). An interaction effect was observed for the relationship between hip external rotation strength and the peak and impulse of the hip extension moment (p = 0.04 and 0.02, respectively), with stronger external rotators related to increased hip extensor moments late in stance in women but not men. Discussion: Although many relationships between hip strength and hip biomechanics during running were non-significant, this study found hip external rotation strength was related to hip frontal plane range of motion (all participants) and the hip extensor moment peak and impulse late in stance in women but not men. Future research may wish to examine measures of strength more closely related to muscle function during running, and its impact on symptoms in people with FAI syndrome. Conflict of interest statement: My co-authors and I acknowledge that we have no conflict of interest of relevance to the submission of this abstract.

Lumbar Bone Mineral Adaptation: The Effect of Fast Bowling Technique in Adolescent Cricketers.

Localized bone mineral density (BMD) adaptation of the lumbar spine, particularly on the contralateral side to the bowling arm, has been observed in elite male cricket fast bowlers. No study has investigated this in adolescents, or the role of fast bowling technique on lumbar BMD adaptation. This study aims to investigate lumbar BMD adaptation in adolescent cricket fast bowlers, and its relationship with fast bowling technique. Thirty-nine adolescent fast bowlers underwent anteroposterior dual x-ray absorptiometry scan of their lumbar spine. Hip, lumbopelvic and thoracolumbar joint kinematics, and vertical ground reaction kinetics were determined using three-dimensional motion capture and force plates. Significant partial (covariate: fat-free mass) and bivariate correlations of the technique parameters with whole lumbar (L1-L4) BMD and BMD asymmetry (L3 and L4) were advanced as candidate variables for multiple stepwise linear regression. Adolescent fast bowlers demonstrated high lumbar Z-Scores (+1.0; 95% confidence interval [CI], 0.7-1.4) and significantly greater BMD on the contralateral side of L3 (9.0%; 95% CI, 5.8%-12.1%) and L4 (8.2%; 95% CI, 4.9%-11.5%). Maximum contralateral thoracolumbar rotation and maximum ipsilateral lumbopelvic rotation in the period between back foot contact and ball release (BR), as well as contralateral pelvic drop at front foot contact, were identified as predictors of L1 to L4 BMD, explaining 65% of the variation. Maximum ipsilateral lumbopelvic rotation between back foot contact and BR, as well as ipsilateral lumbopelvic rotation and contralateral thoracolumbar side flexion at BR, were predictors of lumbar asymmetry within L3 and L4. Thoracolumbar and lumbopelvic motion are implicated in the etiology of the unique lumbar bone adaptation observed in fast bowlers whereas vertical ground reaction force, independent of body mass, was not. This may further implicate the osteogenic potential of torsional rather than impact loading in exercise-induced adaptation.

Topology optimization design and numerical analysis on cold plates for lithium-ion battery thermal management

In this paper, the cold plates are designed to cool the rectangular lithium-ion battery packs by the topology optimization method. The topology optimization method obtains the channel structure in the two-dimensional model, and three-dimensional cold plate models are then established according to their two-dimensional structure. In a simple model for a battery pack, numerical analyses of topology optimization cold plate (TCP) are implemented using COMSOL software. Numerical results were compared with conventional rectangular-channel cold plate (RCP) and serpentine-channel cold plate (SCP) to investigate the cooling performance and flow characteristics of the cold plate. The results demonstrate that the flow channel structure of the cold plate has a significant influence on the temperature distribution of the battery. At 150 Pa inlet pressure, the maximum temperature of batteries with TCPs is reduced by 0.27% and 1.08% compared to that with RCP or SCP, and the temperature difference is lowered by 19.50% and 41.88%. Appropriately increasing the inlet pressure of the cold plate can also reduce the maximum temperature and temperature difference of batteries. Due to low flow resistance and high heat transfer coefficient, topology optimization will be widely used to design battery cold plates.

The effect of an infra-acetabular screw for anatomically shaped three-dimensional plate or standard plate designs in acetabulum fractures: a biomechanical analysis

BackgroundVarious plate shapes and implant configurations are used for stabilization of acetabulum fractures via anterior approaches. Little is known about the biomechanical stability of a two-dimensionally shaped “conventional” plate (“J-Plate”—JP) in comparison to three-dimensionally shaped plate configurations (3DP). In addition, the augmentary effect of an infra-acetabular lag-screw (IACS) fixation for anterior column and posterior hemi-transverse acetabulum fractures has not been clarified in comparison of JP and 3DP constructs. This study analyzed the difference between the biomechanical stability of JP compared to 3DP and the role of an IACS in a standardized acetabular fracture model in a single-leg stance loading configuration.MethodsIn an artificial bone substitute pelvis model (Synbone© Malans, Switzerland), a typical and standardized fracture pattern (anterior column and posterior hemi-transverse) was created with osteotomy jigs. After anatomic reduction the stabilization was performed using JP or 3DP. Eight pelvises per group were axially loaded in a single-leg stance model up to 400 N. After the load cycle, an additional infra-acetabular screw was placed and the measurement repeated. Fragment displacement was recorded by an optical tracking system (Optitrack Prime 13®, Corvallis, USA).ResultsIn the pure placement, 3DP provided significantly superior stability when compared to JP. Augmentation of JP by IACS increased the stability significantly, up to the level of 3DP alone, whereas augmentation of the 3DP did not result in further increase of overall stability.ConclusionThe anatomically shaped plate alone provides a superior biomechanical stability in fixation of an anterior column and posterior hemi-transverse fracture model. In a JP fixation the augmentation by IACS provides similar strength as the anatomically shaped 3DP. By use of the anatomically shaped 3DP the need of a clinically risky application of IACS might be avoidable.Level of evidenceIV, Experimental study.

Open Reduction and Internal Rigid Fixation of Unilateral Displaced Subcondylar Fractures Using a Single Trapezoidal Plate Versus the Traditional Two Miniplates. A Comparative Study.

Purpose: The aim of this study was to compare clinically and radiographically between the single three-dimensional Trapezoidal plate versus the traditional two non-parallel miniplates in ORIF of unilateral displaced subcondylar fractures. Patients and Methods: A total of 24 patients suffering from unilateral displaced subcondylar fractures were randomly divided into two equal groups; Group I patients were treated using single trapezoidal plates while Group II patients were treated using the traditional two miniplates. The clinical parameters include; the Hardware application time, maximum interincisal opening, Protrusive, ipsilateral and contralateral movements, mandibular mobility index, Helkimo index of mandibular dysfunction, facial nerve weakness and plate fracture. Radiographic parameters included: Vertical height of the ramus, anteroposterior and mediolateral condylar angulations. All the clinical and radiographic outcomes were assessed and statistically analysed preoperatively and at all post-operative follow-up intervals. Results: Group I showed a statistically significant lower hardware fixation time in comparison to Group II. Both groups showed no significant difference regarding MMO, protrusive, ipsilateral and contralateral movements. Moreover, the difference regarding vertical ramus height, anteroposterior, and mediolateral condyle angulations was statistically insignificant. Two patients of group II had Plate fracture at the 1-month follow-up interval. Transient weakness of the frontal branch of the facial nerve was observed immediately post-operatively in two patients of group II and recovered completely within 3 months. Conclusion: The results of the present study support the superiority of the single Trapezoidal plates in ORIF of displaced subcondylar fractures with special recommendation for high subcondylar fractures.

A review of biomechanical studies for mandibular angle fracture internal fixation

Mandible fractures correspond to 19-40% of all facial fractures. Among all mandible fractures, 12-30% are fractures of the mandibular angle. These fractures are mainly caused by sports activities, interpersonal violence and car accidents. The presence of the third molar and the thin transverse bone area seem to be responsible for the frequent involvement of the mandibular angle in facial fractures. Before the advent of antibiotics, a high frequency of infection was always associated after an open reduction in mandibular angle fractures. Wired osteosynthesis and maxillomandibular fixation (MMF) were traditional methods for fixing mandibular angle fractures. The limitation of both methods has influenced the development of new approaches for the treatment of mandibular angle fractures. Currently, osteosynthesis of mandibular angle fractures with plates and screws has become an effective treatment option. Several forms are described in the literature as: fixation of bone segments with a miniplate on the upper edge of the mandible, fixation with two miniplates, lag screw or by a single rigid plate on the lower edge of the mandible. The purpose of this study was to summarize the main characteristics of biomechanical studies such as the type of mandible source used, the plating techniques employed, the plate material, and the loading protocols used to evaluate the stability of the fixation methods. The Medline (PubMed) database was searched combining relevant terms and pertinent articles in English were included. Articles had to meet the following inclusion criteria: be in vitro biomechanical studies evaluating fixation methods for mandibular angle fractures. A total of 27 articles fulfilled the inclusion criteria. Synthetic mandibles (n=12), animal mandibles (n=9), and human cadaveric mandibles (n=5) were used as the sample source to perform the biomechanical analysis. One article used both synthetic and human cadaveric mandibles. Also, a variety of fixation techniques was described such as mini-plates, lag-screws, reconstruction plates, and three-dimensional plates. The materials of the bone plates used were: stainless steel, commercially pure titanium, titanium alloy or bioresorbable. However, there was inconsistency in reporting the materials and not all studies clearly stated the material of the bone plates. For the biomechanical analysis, there was a high variation among all studies regarding the loading protocols used. The same side of fixation, the anterior part of the mandible (central incisors) or the contralateral side were reported as the dentate regions in which the force was applied. For more than 2 decades, in vitro biomechanical studies have been used to help researchers and clinicians in the field of Oral and Maxillofacial Surgery to properly evaluate and compare the different devices and techniques available for the treatment of mandibular angle fractures. Also, biomechanical studies are important to answer questions on fatigue performance and fracture strength on the gross level.

Mathematical simulation of adaptive vector finite element method for the analysis of electromagnetic vibration spectrum field response

Mathematical simulation plays a vital role in the analysis of electromagnetic vibration spectrum field response. This article realizes a three-dimensional adaptive vector finite meta-acting algorithm of controlled source electromagnetic vibration spectrum (CSEM) field to address 3D meshing for the simulation of terrain fluctuations and complex electrical anomalies. The adaptive methods utilized in this article is employed for one-time field and secondary field separation in order to calculate electromagnetic vibration spectrum field response. This response can effectively solve the source singularity in finite meta-simulation and improves the numerical accuracy of electromagnetic vibration spectrum field near the field source. The two approaches analysed in this article are CSEM one-dimensional positive algorithm and finite meta-method. The adaptive mesh refinement algorithm based on post-test error estimation is used in this paper to guide the mesh refinement to reduce man-made errors caused by designing a grid. The validity of the proposed algorithm is verified through numerical simulation of one-dimensional and three-dimensional models. The outcomes obtained reveals that the finite solution of one-dimensional model coincides well with the analytical solution. The relative error of electromagnetic vibration spectrum field amplitude is about 1 %, and the overall phase difference of less than 1 degree is observed. It is analysed that the three-dimensional model finite solution also fits well with the finite volume solution and the controlled source electromagnetic vibration spectrum response with three-dimensional tilt plate abnormality is simulated. This experimental analysis shows the ability and effectiveness of the algorithm to simulate the electromagnetic vibration spectrum field of complex geoelectrical structure.

Physical–numerical parameters in laminar simulations of natural convection on three-dimensional square plates

PurposeThe purpose of this study is to analyze the influence of the main physical–numerical parameters in the computational evaluation of natural convection heat transfer rates in isothermal flat square plates in the laminar regime. Moreover by experimentally validate the results of the numerical models and define the best parameter settings for the problem situation studied.Design/methodology/approachThe present work is an extension of the study by Verderio Junior et al. (2021), differing in the modeling, results analysis and conclusions for the laminar flow regime with . The analysis of the influence and precision of the physical–numerical parameters: boundary conditions, degree of mesh refinement, refinement layers and κ – ω SST and κ – ε turbulence models, occurred from the results from 48 numerical models, which were simulated using the OpenFOAM® software. Comparing the experimental mean Nusselt number with the numerical values obtained in the simulations and the analysis of the relative errors were used in the evaluation of the advantages, restrictions and selection of the most adequate parameters to the studied problem situation.FindingsThe numerical results of the simulations were validated, with excellent precision, from the experimental reference by Kitamura et al. (2015). The application of the κ – ω SST and κ – ε turbulence models and the boundary conditions (with and without wall functions) were also physically validated. The use of the κ – ω SST and κ – ε turbulence models, in terms of cost-benefit and precision, proved to be inefficient in the problem situation studied. Simulations without turbulence models proved to be the best option for the physical model for the studies developed. The use of refinement layers, especially in applications with wall functions and turbulence models, proved unfeasible.Practical implicationsUse of the physical–numerical parameters studied and validated, and application of the modeling and analysis methodology developed in projects and optimizations of natural convection thermal systems in a laminar flow regime. Just like, reduce costs and the dependence on the construction of experimental apparatus to obtain experimental results and in the numerical-experimental validation process.Social implicationsExclusive use of free and open-source computational tools as an alternative to feasible research in the computational fluid dynamics area in conditions of budget constraints and lack of higher value-added infrastructure, with applicability in the academic and industrial areas.Originality/valueThe results and discussions presented are original and new for the applied study of laminar natural convection in isothermal flat plate, with analysis and validation of the main physical and numerical influence parameters.

Isogeometric analysis for free vibration of bidirectional functionally graded plates in the fluid medium

This paper for first time proposes an isogeometric analysis (IGA) for free vibration response of bi-directional functionally graded (BDFG) rectangular plates in the fluid medium. Material properties of the BDFG plate change in both the thickness and length directions via power-law distributions and Mori-Tanaka model. The governing equation of motion of BDFG plate in the fluid-plate system is formulated basing on Hamilton's principle and the refined quasi three-dimensional (3D) plate theory with improved function f(z). The fluid velocity potential is derived from the boundary conditions of the fluid-plate system and is used to determine the added mass. The discrete system of equations is derived from the Galerkin weak form and numerically analyzed by IGA. The accuracy and reliability of the proposed solutions are verified by comparing the obtained results with those published in the literature. Moreover, the effects of the various parameters such as the interaction boundary condition, geometric parameter, submerged depth of plate, fluid density, fluid level, and the material volume control coefficients on the free vibration behavior of BDFG plate in the fluid medium are investigated in detail. Some major findings regarding the numerical results are withdrawn in conclusions.

Interplay of chordwise stiffness and shape on performance of self-propelled flexible flapping plate

The locomotion of a flapping flexible plate with different shapes and non-uniform chordwise stiffness distribution in a stationary fluid is studied numerically. The normalized effective bending stiffness K∗ for three-dimensional plates with arbitrary stiffness distribution and shape parameters is proposed, and the overall bending stiffness of non-uniform plates with different shapes is reasonably characterized. It is found that the propulsion performance in terms of cruising speed and efficiency of the self-propelled flapping plate mainly depends on the effective bending stiffness. Plates with moderate flexibility K∗ show better propulsion performance. Meanwhile, both a large area moment of the plate and a flexible anterior are favorable to significantly improve their propulsive performance. The evolution of vortical structures and the pressure distribution on the upper and lower surfaces of the plate are analyzed, and the inherent mechanism is revealed. These findings are of great significance to the optimal design of propulsion systems with different fins or wings.