Auxiliary Plate Research Articles

Analysis of Thickness Variation in 2219 Aluminum Alloy Ellipsoid Shell with Differential Thickness by Hydroforming

The process of spinning and machining for heavy plates has the problems of a large amount of machining, large springback, and easy cracking. Aiming to address these issues, we proposed a deep drawing forming method for a plate with differential thickness to manufacture an integral ellipsoid component with a thin zone in the middle and a thick zone in the periphery. The plate with a differential thickness was initially produced through machining, followed by the execution of deep drawing deformation. During the deformation process of plates with differential thickness, the thin zone is prone to rupture defects. Therefore, a hydroforming method utilizing an elastic auxiliary plate was adopted to solve this problem. Through mechanical analysis and deep drawing experiments, the influences of hydraulic pressure and elastic auxiliary plate on the distributions of thickness and strain were studied, and the influence of friction on hydroforming was analyzed. The results indicate that increasing the hydraulic pressure and setting elastic auxiliary plates can increase the interfacial friction, reduce the thickness thinning rate, and improve the thickness distribution and deformation uniformity within the thin zone. When the hydraulic pressure is 5.2 MPa and the thickness of the elastic plate is 5 mm, the maximum thickness thinning rate of the ellipsoid shell is 8.8%, which is 34% lower than that of the ellipsoid shell obtained via conventional deep drawing.

Combined anatomical reduction plate for quadrilateral acetabular fractures via a posterior approach: an anatomical–morphological study

ObjectiveTo digitally measure the fixation trajectory of anatomical plates used in the combined reduction of quadrilateral acetabular fractures via the posterior approach, and to develop anatomical plates that align with the characteristics of the pelvis in the Chinese population.MethodsPelvic computed tomography (CT) data from 102 adult patients were collected at the Affiliated Hospital of Zunyi Medical University. This group included 51 males and 51 females, aged between 20 and 60 years. Using Mimics software (version 21.0), a three-dimensional model of each pelvic data point was reconstructed. The fixation path for the combined reset anatomical steel plate was drawn, where the curves on the fixation path were approximated as arcs. The radius of curvature and length of these curves were measured, and an anatomical steel plate was designed to best fit the pelvic structure.ResultsThe combined anatomical reduction plate fixation system for quadrilateral acetabular fractures using a posterior approach consisted of two parts: a locking plate and a reduction plate. The posterior wall region (r2), ischial region (r3), quadrilateral region (r4), and bending region (r5), and the total length of the reduction plate were significantly smaller in females (P < 0.05). Similarly, the posterior wall region (R3), distal posterior wall region (R4), and the total length of the locking plate were significantly smaller in females (P < 0.05). Additionally, the anterior superior iliac spine side (r1) and the total length of the T-shaped auxiliary plate were significantly smaller in females (P < 0.05). The bending angle (< A) was also significantly smaller in females (P < 0.05).ConclusionsThe pelvic surface structure is irregular and varies greatly among individuals.Compared to the traditional steel plate, The combined reduction anatomical plate designed in this study demonstrated high precision and improved conformity to the anatomical structure of the pelvis.

Thermomechanical vibration and buckling response of magneto-electro-elastic higher order laminated nanoplates

This study investigated the free vibration and buckling behavior of a magneto-electro-elastic (MEE) sandwich porous nanoplate under nonlinear thermal loads and electric and magnetic potentials. The equation of motion of the nanoplate consisting of barium-titanate and cobalt-ferrite components, with a functionally graded (FG) porous core and two face plates, was modeled by a sinusoidal higher-order shear (SHSDT) and the nonlocal strain gradient (NSGT) theories. Due to the significant effect of the temperature in the dynamics of the magneto-electro-elastic nanoplate, the temperature-dependent material properties of barium-titanate (BaTiO3) and cobalt ferrite (CoFe2O4) were defined and applied to the modeling for the first time in the literature. The laminated plate consists of upper and lower surface auxiliary plates and a main FG core plate. The core plate consists of functionally grading cobalt-ferrite and barium-titanate, while face plates can be in three different material compositions consisting of pure cobalt-ferrite, pure barium-titanate, or a combination of the two. It has been shown in this study that the dynamic behavior of the core plate, exposed to high temperatures, can be controlled through auxiliary surface plates. Especially in nanosensor applications, the disadvantage of thermal load can be reduced by the electric and magnetic field's strength applied to the surface plates. This study will make an essential contribution to the design and application of nanosensor or nanoelectromechanical systems, especially by controlling nanosensor responses in high-temperature applications.

Research on hydroforming of 5A06 aluminum alloy semi-ellipsoid shell with differential thickness

For the purpose of eliminating the annular welding seams in welding structures with differential thickness, a hydroforming method using a circular 5A06 aluminum alloy plate with a radial differential thickness in coupling with a flexible polyurethane auxiliary plate was proposed to form an integrated semi-ellipsoid shell. The circular 5A06 aluminum alloy plate had a smaller in the middle and a larger thickness in the periphery. In the forming process of such aluminum alloy plates, concentrated deformation and fracture might have occurred in the thin zone. According to the size of the target specimen, the testing plates with two types of thickness ratios were obtained by mechanical processing. Furthermore, the thickness and strain of the drawn specimens with different thickness ratios were analyzed under different hydraulic pressure by means of deep drawing experiments. Compared to the conventional deep drawing, the formability of 5A06 aluminum alloy plates with differential thickness could be effectively improved by hydroforming. The integrated semi-ellipsoid shells with the thickness ratios of 2/3 and 1/2 were obtained under the hydraulic pressure of 10 MPa with maximum thinning ratios of 8.5% and 10.9%, respectively. In a word, the increase in hydraulic pressure could effectively reduce the maximum thinning ratio in the thin zone, and improve the thickness distribution uniformity.

A study on the effect of metal skeleton auxiliary heating device on microwave heating efficiency of batch Al2O3 ceramics

In order to improve the microwave heating efficiency of the batch Al2O3 ceramics, according to generalized transmission line theory in this paper, the relationship between the amplitude and phase of the electromagnetic field in the microwave resonant cavity was deduced by using the distribution relationship of voltage and current on the transmission line. SiC auxiliary heating plate was used as the auxiliary heating device. Based on the reflection principle of metal material to electromagnetic wave, the metal skeleton was added to SiC auxiliary heating plate. The COMSOL multi-physics field simulation software was used for simulation. The results showed that the addition of metal materials could change the intensity and distribution of the electromagnetic field on SiC auxiliary heating plate and Al2O3 ceramic blocks, so as to affect the microwave energy utilization rate of heating area and the heating efficiency of Al2O3 ceramic blocks. The numerical simulation results showed that the microwave energy utilization rate of the heating area could be improved by adding the metal skeleton in the SiC auxiliary heating plate and employing a reasonable design, so as to improve the overall heating efficiency of the Al2O3 ceramic blocks. Compared with the traditional SiC auxiliary heating device, the heating efficiency of Al2O3 ceramic blocks was improved by 26.4%, and the overall temperature uniformity was improved by 12.5%.

Study on High-Strain-Rate Deformation of Magnesium Alloy Using Underwater Shock Waves Generated by High-Voltage Electric Discharge of Thin Wire

Magnesium is an abundant material with high specific strength, and its use as a structural metal is increasing. However, its properties cause difficulty in its formation at room temperature. Therefore, the objective of this study was to form a magnesium alloy at room temperature using an underwater shock wave generated by the discharge of an aluminum wire. Forming was conducted using an auxiliary plate composed of aluminum instead of magnesium alloy alone. In addition, hyperbolic and parabolic pressure vessels were employed. Numerical simulations were performed to measure the pressure values, propagation of underwater shock waves, and deformation of the magnesium alloy. Large deformation was observed when an auxiliary aluminum plate was placed on the upper surface of an AZ31 magnesium alloy plate inside the hyperbolic pressure vessel.

Prevention and treatment of complications in the treatment of femoral shaft closed fracture with core drilling intramedullary nail

To summarize the complications of core drilling intramedullary nail in the treatment of femoral shaft closed fracture and explore the treatment strategy. From August 2014 to June 2018, a total of 215 patients with closed femoral shaft fractures were treated with closed reduction core drill intramedullary nail, including 129 males and 86 females, aged from 18 to 62 years, with an average of (44.2±10.6) years old. The time from injury to operation was 3 to 21 days. There were 102 cases of AO type A fracture, 82 cases of AO type B fracture and 31 cases of AO type C fracture. The time of operation, the amount of blood loss during operation, the duration of hospitalization, the time of fracture healing and the HSS score of knee joint function at the last follow-up were recorded. The observation of complications included:iatrogenic fracture, core drill broken, core drill twist, postoperative infection, and fracture nonunion. The average operation time was (63.2± 15.6) min and intraoperative blood loss was (150.0±34.5) ml. All the incisions reached grade A healing. Patients were follow up for a mean of (18.5±3.2) months, the average hospital stay was (4.3±1.2) days, and the average fracture healing time was (5.6±2.3) months. At the final follow-up, the average HSS score of knee joint was 90.3±4.7. Related complications occurred in 37 cases (17.2%). The core drill related complications occurred in 13 cases (6.0%), including core drill broken in 5 cases (2.3%), core removal in 1 case and slotting in 4 cases;core drill twist in 8 cases (3.7%). After the core was cut, the core was removed. Similar complicationsof conventional intramedullary nail:iatrogenic fracture was performed in 12 cases (5.6%), including 10 cases of fracture end split and 2 cases of distal perimedullary fracture of intramedullary nail. The patients with cleavage at the fracture end were not treated after judging their stability, and the patients with fracture around the distal end of the intramedullary nail were fixed with auxiliary steel plate during operation;1 case(0.4%) with delayed infection after operation, debridement and external fixation was replaced and healed after bone transfer; fracture nonunion occurred in 11 cases (5.1%), of which 7 cases (3.3%) were hypertrophic nonunion and healed with additional plate. Atrophic nonunion occurred in 4 cases (1.9%), which healed after additional steel plate and bone graft. Core drilling intramedullary nail is an effective method for the treatment of closed femoral shaft fracture, and the complications include core drill related complications and conventional intramedullary nail similar complications. Accurate preoperative evaluation, careful operation during operation and early postoperative symptomatic treatment can effectively reduce the occurrence of related complications.

Identification of Engine Inertia Parameters and System Dynamic Stiffness via In Situ Method

An in situ method is presented to identify ten engine inertia parameters and system dynamic stiffness from the frequency response functions. The ten engine inertia parameters and system dynamic stiffness are estimated from two distinct steps. The accuracy of the proposed technique is verified by finite element simulation, and then the generality is validated using an engine supported by a specially designed curved bar spring. The locations of the measure points on the results are also carefully investigated. The identification of system dynamic stiffness is validated comparing with the engine with an auxiliary plate, which shows good consistency with the results identified from the study.

Fatigue and Stress Analysis of a Load Carrying Car Chassis with Reinforced Joint Using Finite Element Method

In this article, a case study of a load-carrying vehicle chassis with various loading conditions in six maneuvers has been conducted. These maneuvers include acceleration and deceleration in a loaded and un-loaded situation, drops, pothole, turn, and sinusoidal obstacles. Finite element analysis has been implemented in order to calculate stress distribution and fatigue life. Stress analysis indicated that the joints stiffness is higher where the auxiliary profiles were utilized. However, this procedure is cumbersome and auxiliary plates would be a more efficient strategy. The effects of using auxiliary plates have been investigated in the fatigue and stress distribution of the aforementioned chassis. The analysis revealed that the 300 mm drop has the maximum tension and accordingly embodies the shortest fatigue life. Furthermore, for welding joints, three different strategies for geometry configuration including welding bead, reinforcing plates, and extra auxiliary profiles under the welded joints were assumed.

The flexible rolling process of three-dimensional curved parts using an auxiliary plate based on rigid arc-shaped rollers

The flexible rolling process of three-dimensional curved parts using an auxiliary plate based on rigid arc-shaped rollers

Results of revision intramedullary nailing with and without auxillary plate in aseptic trochanteric and subtrochanteric nonunion

PurposeAim of this study was to investigate whether limited open auxiliary angle stable plate fixation has an effect on functional and radiologic outcomes one year after revision intramedullary nailing in aseptic trochanteric and subtrochanteric fracture nonunion.MethodsIn a retrospective analysis, surgically revised aseptic trochanteric and subtrochanteric nonunion was evaluated in a total of 190 consecutive patients ranging from 18 to 94 years between 12/2005 and 10/2018.ResultsOne year after revision intramedullary nailing, nonunion healing was assessed in 129 out of 136 patients (95%) in group 1 without auxiliary plate fixation and in 51 out of 54 patients (94%) in group 2 with auxiliary plating (p = 0.23). In group 1, range of motion (ROM) was unrestricted in 88 patients and still restricted in 48 patients. In group 2, ROM was free in 34 patients and restricted in 20 patients (p = 0.25). The mean Lower Extremity Functional Scale (LEFS) was 56 points in group 1 and 55 points in group 2 (p = 0.55).ConclusionThis study did not demonstrate significant differences in functional and radiologic outcomes following revision intramedullary nailing of aseptic trochanteric and subtrochanteric fracture nonunion. Limited open auxiliary plate fixation might be a reasonable option especially in cases of relevant varus axis deviation and comminuted or atypical fracture configurations, regardless of patients’ age.Retrospectively registered with the German Clinical Trials Register (01/25/2021; ID: DRKS00024112).

Preliminary test of a newly developed pilot-scale movable microwave drying equipment for the treatment of solid organic waste

This study introduces a developed, movable, and pilot-scale microwave drying equipment with an automatic control system for the treatment of solid organic waste. Based on a previous study, the structure of the reactor and the arrangement of the magnetron were improved to make the material absorb microwave energy more uniformly and efficiently. The equipment added the auxiliary hot plate and air extraction system, which effectively solved the influence of the occurrence condensate water in the microwave irradiation room on the drying efficiency and energy consumption. The microwave drying behavior of the existing constant-power mode was compared with the improved constant-temperature mode. The experimental results showed that the latter mode could effectively solve the partial overheating of the material caused by uneven heating. The constant-temperature mode was more advantageous in product quality, safety, and selectivity. The advantages and disadvantages of the equipment were analyzed by comparing it with the other existing pilot-scale microwave drying equipment. The proposed system showed good performance. Thus, the newly developed mobile microwave drying system has great potential for practical application.

Technological Features in Processing of Conical Lenses

The paper presents the technology of obtaining flat-conical lenses (axicons) by the method of free grinding a work-piece to a flat tool through a layer of abrasive suspension. For this, theoretical and experimental studies of the regularities of stock removal from the base of the cone and its lateral surface have been carried out. The processing modes have been identified that ensure both uniform operation of the flat surface of the part and enhanced removal of the allowance in the edge or central zone of this surface. During the study of the processing of the conical surface, the set-up parameters of the technological equipment have been established, at which there is a minimum deviation of the generatrix of the cone from straightness and maximum productivity of the process. The stages of processing conical lenses are proposed, which allow to assign the optimal sequence of operations in the manufacture of this type of parts from blanks of a cylindrical shape in cases where the ratio of the height of the cone to the diameter of its base H/d £ 0.5. The main stages of processing include: grinding of the bases of cylindrical blanks with maintaining their mutual parallelism with a given accuracy; polishing one of the cylinder bases to achieve the required roughness and deviation from non-flatness; fastening a cylindrical blank to an auxiliary plane-parallel glass plate using molecular cohesion forces; mechanical fastening of a cylindrical work-piece with a collet adapter mandrel for a plane-parallel glass plate; applying the nearest sphere to the second base of the cylindrical blank; drawing a conical surface on the spherical part of a plano-convex lens; grinding and polishing the conical surface to achieve the required roughness and straightness of the cone generatrix. The degree of efficiency of the setup parameters of the machine has been revealed depending on the technological heredity of the work-piece from the point of view of the distribution of the allowance to be removed over the machined surface.

Characterization of mechanical properties and structure of structural steel welds using different fluxes

In this analysis, impact of Basicity record on the welding attributes was dissected in the lowered bend welding by keeping all other variable keeping steady like current, voltage and welding speed. The impacts of wire/transition (Basicity file) on extreme elasticity, Microstructure and effect quality of the weld metal were examined. Weld stores on auxiliary steel plates were made at various motion organization. The examination was finished with the point of considering the impact of basicity list on mechanical properties of basic steel. The goal was to lessen the deformities and improving the mechanical properties. In this analysis plates of measurement 14 × 125 × 250 mm were utilized for welding. The examples were removed from the welded plate to complete different tests in the wake of playing out the saw activity. Five distinct sorts of transitions were utilized to weld the plates. The outcomes indicated that the effect sturdiness esteems at room temperature increments with increment in basicity file of transition and most elevated miniaturized scale hardness esteems are shaped at the HAZ areas for welded examples.

Clinical Analysis on the Treatment of Kaschin-Beck Disease of the End-Stage Ankle by Tibiotalocalcaneal Arthrodesis Using Lateral Approach With Platelet-Rich Plasma

Category:Ankle Arthritis; AnkleIntroduction/Purpose:Objective To study the effectiveness of treated Kaschin-Beck Disease of the ankle by tibiotalocalcaneal arthrodesis using lateral approach with autologous platelet-rich plasma.Methods:Retrospective analysis was conducted on the clinical effect of our department on the treatment of 23 patients (25 ankle joints) with severe Kaschin-Beck Disease from May 2014 to May 2016. All patients were treated with tibiotalocalcaneal arthrodesis by using lateral approach of fibula osteotomy with distal fibula cancellous bone combined with autologous platelet rich plasma for bone grafting and internal fixation with full thread cannulated screws or auxiliary lateral plate. Surgical time, blood loss, joint fusion time, delayed wound healing, infection, nonunion of osteotomy surface, chronic pain and other complications were recorded. VAS score and AOFAS ankle and hind foot score were compared before and at the last follow-up.Results:The mean healing time was 14.7 weeks. Postoperative wound healing was delayed in 3 patients. One patient developed superficial infection 1 week after surgery. Bone graft absorption, nonunion of osteotomy surface and loosening of internal fixation were observed in 2 patients. The bone healed at 13 weeks after surgery. 22patients were followed up for an average of 15.7 months. The postoperative AOFAS score was 76 points, and the postoperative VAS score was 2 points with statistically significant differences from the preoperative AOFAS (t=19.13, P<0.01) and VAS (t=17.27, P<0.01). In 21 cases, tibial calcaneal joint fusion was performed in the first stage, and the fusion rate was 87.5%.21 patients received the first stage of bone fusion after surgery, and the fusion rate was 87.5%.Conclusion:Ankle joint and subtalar joint can be well exposed through the lateral approach of fibular osteotomy. The distal fibula autograft with sufficient cancellous bone mass and the combination of autologous platelet rich plasma graft can promote bone healing, and the reliable internal fixation can help achieve satisfactory clinical effect of tibiotalocalcaneal arthrodesis.

Application of "diamond concept" in treatment of femoral shaft fractures nonunion after intramedullary fixation

To investigate the effectiveness of the treatment under the guidance of "diamond concept" for femoral shaft fractures nonunion after intramedullary fixation. Between January 2014 and December 2016, 21 cases of femoral shaft fractures nonunion after intramedullary fixation were treated with auxiliary plate fixation combined with autogenous iliac graft, and autologous bone marrow concentrate and platelet-rich plasma (PRP) gel under the guidance of the "diamond concept". There were 13 males and 8 females, with an average age of 32.5 years (range, 17-48 years). All fractures were closed femoral shaft fractures. Four patients underwent internal fixation with plate and resulted in nonunion, then they were fixed with intramedullary nails, but did not heal either. The rest 17 patients were fixed with intramedullary nailing. Fracture nonunion classification: 4 cases of hypertrophic nonunion, 17 cases of atrophic nonunion; the length of bone defect was 1-3 mm; the duration from the last treatment to the current treatment was 10-23 months (mean, 14.3 months). The operation time, intraoperative blood loss, the time between operation and full loading, fracture healing time, and complications were recorded. The visual analogue scale (VAS) score and the imaging system of fracture healing of the extremities (RUST) of patients before operation and at last follow-up were recorded to evaluate the fracture healing; the function of the affected limb was evaluated according to the Schatzker-Lambert efficacy score standard at last follow-up. The operation time was 105-160 minutes, with an average of 125.6 minutes; the intraoperative blood loss was 160-580 mL, with an average of 370.5 mL. All incisions healed by first intention, without vascular or nerve injury. All patients were followed up 22-46 months (mean, 26.5 months). All the fractures healed, with a fracture healing time of 3-7 months (mean, 4.8 months). During the follow-up, there was no infection, loosening, implant breakage, re-fracture, and other complications. The VAS score at last follow-up was 0.8±0.3, showing significant difference ( t=7.235, P=0.000) when compared with preoperative score (5.2±3.7); the RUST score was 3.4±0.3, which was significantly higher than the preoperative score (1.5±0.7) ( t=8.336, P=0.000). According to the Schatzker-Lambert effectiveness evaluation standard, the limb function was excellent in 16 cases, good in 4 cases, fair in 1 case, and the excellent and good rate was 95.42%. Nonunion after intramedullary fixation of femoral fracture treated with auxiliary plate combined with autogenous iliac graft, autogenous bone marrow concentration and PRP gel in accordance with the "diamond concept" can not only restore the stability of the fracture ends, but also improves the biological environment of the fracture site, and can improve the rate of fracture healing.

Effects of auxiliary heat on warpage and mechanical properties in carbon fiber/ABS composite manufactured by fused deposition modeling

Fused Deposition Modeling (FDM) technology offers opportunities for high-efficiency design and low-cost manufacturing of 3D complex parts in additive manufacturing (AM). The warpage remains a big problem which prevents the industrial application of FDM parts, especially parts fabricated by fiber-reinforced composite. In this study, an auxiliary heating plate was developed and mounted on the printing head of an FDM 3D printer to suppress the warpage of the parts made with short carbon fiber (CF)-reinforced acrylonitrile-butadiene-styrene copolymers (ABS) composites. It is found that auxiliary heating and raster angle of FDM process are the two dominating parameters on the tensile properties and the warpage of FDM parts. For the best parameter combination, 160 oC for auxiliary heating temperature and 0 degree for raster angle, the warpage was completely suppressed and the tensile strength got 31% enhancement, ductility got 439% enhancement compared to the FDM part without auxiliary heating and 0 degree in raster angle. Cyclic fatigue behavior and anisotropy of CF/ABS specimen was also significantly improved by auxiliary heating treatment. The reduced stain caused by the annealing ability of auxiliary heating during the 3D printing, is responsible for this enhancement. Compared with auxiliary heating and post thermal annealing treatment, the tensile property and cyclic fatigue behavior of CF/ABS specimen was equivalent. Notably, auxiliary heating is the “in-situ” annealing during the process of 3D printing, which can break through the existing dimension constraints of post thermal annealing treatment. Therefore, the approach broadens the design for CF/ABS composites through temperature-specific optimization and makes it possible to fabricate huge-size FDM parts.

Estimation and clinical verification of the effective and skin doses for pediatric and adult patients undergoing the cardiac interventional examination using five PMMA phantoms and TLD/ionization chamber technique.

BACKGROUND:Effective and skin doses gain much attention since the cardiac catheterization laboratory (CCL) is a place where both patients and medical staff are exposed to X-ray or fluoroscopy environment and gain a cumulative dose during the cardiac interventional procedure.OBJECTIVE: These doses for pediatric and adult patients undergone cardiac interventional examination using five PMMA phantoms and thermoluminescence dosimeter (TLD)/ionization chamber technique were estimated in this work with the further clinical verification.METHODS: Five PMMA phantoms (10, 30, 50, 70, and 90 kg) were customized to represent baby, child, adult female, adult male, and overweight adult (by Asian complexion standards), respectively, in accordance with the ICRU-48 report. Each phantom could be disassembled into 31 plates to insert TLD chips for measuring X-ray exposed dose or assisted with an auxiliary plate to insert high-sensitivity ionization chamber for surveying low-energy fluoroscopy dose.RESULTS: The data acquired from five phantoms were integrated into four semi-empirical formulas, in order to fit the binary quadratic form “Dose ABMI+BDAP+CBMI+ DDAP+E”. The latter linked the X-ray and fluoroscopy effective/skin doses, respectively, with a high coefficient of determination (from 0.888 to 0.986).CONCLUSIONS:The model refinement with DAP share adjustment is envisaged.

High Water‐Absorbent and Phase‐Change Heat Dissipation Materials Based on Super‐Aligned Cross‐Stack CNT Films

Carbon nanotubes (CNTs) with the advantage of high thermal conductivity and light weight can be widely used in thermal management. Meanwhile, heat removal for hot spots has become a major issue in the development of electronics because of the increasing of power density and thermal load. Therefore, more effective heat dissipation approaches are needed. Here, the high water‐absorbent and phase‐change heat dissipation materials based on super‐aligned cross‐stack CNT (CSCNT) films with excellent cooling performance are reported. Pure CSCNT and CaCl2/CSCNT composite show the outstanding water absorption property because of their high specific surface area and porosity. Combined the high natural convection and heat radiation of CSCNTs with heat removal by water evaporation, the heat dissipation coefficient of CaCl2/CSCNT can reach as high as 98 W m−2 K−1 with the help of auxiliary plate. Due to the high absorption rate, the composite can absorb water when electronics are at low power and dissipate heat by water evaporation at high power. Moreover, it is founded that there is a dynamic balance of water absorption and desorption to enhance cooling performance at thermal equilibrium.

Novel Nozzle Shapes for Synthetic Jet Actuators Intended to Enhance Jet Momentum Flux

An axisymmetric synthetic jet actuator based on a loudspeaker and five types of flanged nozzles were experimentally tested and compared. The first (reference) type of nozzle was a common sharp-edged circular hole. The second type had a rounded lip on the inside. The third nozzle type was assembled from these two types of nozzles—it had a rounded lip on the inside and straight section on the outside. The fourth nozzle was assembled using orifice plates such that the rounded lips were at both inner and outer nozzle ends. The last nozzle was equipped with an auxiliary nozzle plate placed at a small distance downstream of the main nozzle. The actuators with particular nozzles were tested by direct measurement of the synthetic jet (SJ) time-mean thrust using precision scales. Velocity profiles at the actuator nozzle exit were measured by a hot-wire anemometer. Experiments were performed at eight power levels and at the actuator resonance frequency. The highest momentum flux was achieved by the nozzle equipped with an auxiliary nozzle plate. Namely, an enhancement was approximately 31% in comparison with an effect of the reference nozzle at the same input power. Furthermore, based on the cavity pressure and the experimental velocity profiles, parameters for a lumped element model (mass of moving fluid and pressure loss coefficient) were evaluated. These values were studied as functions of the dimensionless stroke length.