Optimal Angle Research Articles

Integrated simulation method construction and process optimization for hot air drying of shiitake mushrooms

Currently, numerical simulations are conducted at the level of dryers without considering the actual moisture evaporation within agricultural materials. This departure from reality fails to meet the requirements of actual industrial production. To address this issue, this paper proposes a drying kinetic derivative model based on experiments conducted on shiitake mushrooms' drying kinetics. With the help of this model, we can determine the moisture evaporation rate under varying drying conditions. Based on the evaporation rate, a material-dryer integrated simulation method is developed to achieve coupling between the material and the dryer. Finally, the simulation method is used to investigate the non-uniform distribution of the moisture ratio of shiitake mushrooms in the dryer, optimize the inlet parameters of the dryer, and improve its internal structure. Through optimization, it was determined that the optimal angle for the baffle is 45° with a width of 65 mm, which can reduce the unevenness of moisture content by 25.84% and decrease the total drying time by 0.59 h. This research not only contributes to the thorough analysis of the distribution of various physical fields within the dryer, optimization of drying conditions, and structural parameters of the dryer but also offers valuable reference for studying and optimizing the drying industrial conditions of other materials. This research holds significant implications for the industrial advancement of the drying sector.

Management of lateral misalignment loss and total insertion loss with beam waist control in high contrast single mode coupling fibers

Abstract This paper has illustrated the management of lateral misalignment loss and total insertion loss with beam waist control in high contrast single mode coupling fibers. The beam waist variations are clarified versus the fiber coupler wavelength and coupling length variations for the silica glass/fluoride glass fiber coupler with the optimum incident beam angle of 60°. Besides, the coupling loss is demonstrated against the fiber coupler wavelength and coupling length variations for the silica glass/fluoride glass fiber coupler with the optimum incident beam angle of 60°. The optimum beam waist and optimum coupling loss are deeply studied against the fiber coupler core radius variations for the silica/fluoride glass fiber coupler with the optimum incident beam angle of 60° and wavelength of 1,550 nm.

Optimization of Magnetic Core Structures for Enhanced Magnetic Coupling in Helical Coil Inductive Power Transmission

Inductive power transfer (IPT) systems often encounter limitations in efficiency and transmission distance due to near-field magnetic coupling characteristics. Increasing the inductance can enhance the transmission distance, but it also raises the system’s Q factor, leading to several issues. This study aimed to optimize the magnetic core design of helical coils to enhance magnetic coupling in IPT systems while minimizing the increase in self-inductance. Through finite element analysis, various core placements were evaluated, leading to a proposed core design process that integrates inner and lower cores at optimal angles. The proposed design was compared with conventional cores, and its performance was validated in an IPT system. The results demonstrate that the proposed core design significantly enhances the coupling coefficient (k) and extends power transmission distance compared with conventional planar and U-shaped core structures without substantially increasing self-inductance (L). This design effectively balances the trade-off between increasing inductance and maintaining system stability, thereby improving transmission efficiency while minimizing frequency instability and voltage stress.

Coordinated Control of Constant Output Voltage and Maximum Efficiency in Wireless Power Transfer Systems

This article presents a coordinated control method used for wireless power transfer (WPT) systems. This method can improve WPT system transmission efficiency while maintaining the constant output voltage. First, the topology of the DC–DC converter is selected and the equivalent circuit model of the WPT system is established. Then, the WPT system characteristics are discussed and the mutual inductance estimation process is presented. Furthermore, the coordinated control method is proposed, where the constant voltage output is achieved by connecting the Buck–Boost converter after the diode rectifier. Meanwhile, the optimal phase shift angle is calculated and sent to the controller to achieve maximum transmission efficiency tracking control, according to the measured load voltage and current. Finally, simulations and experiments are adopted to verify the proposed coordinated control method. The experimental results indicate that the average system transmission efficiency is increased by 1.80% and the efficiency fluctuation is decreased by 2.67% when the system load resistance varies, while the average system transmission efficiency is increased by 1.80%, and the efficiency fluctuation is decreased by 3.14% when the mutual inductance changes. This means the proposed coordinated control method is effective under the conditions of the WPT load and mutual inductance variations.

Deep reinforcement learning-aided minimum current control for the DBSRC based on harmonic analysis method

Aiming to optimize the modulation efficiency for the dual-bridge series-resonant converter (DBSRC), this paper proposes an deep reinforcement learning (DRL) aided EPS (DEPS) modulation scheme for minimum current operation based on the harmonic analysis method. Using the deep deterministic policy gradient (DDPG) algorithm as an advanced DRL algorithm, the scheme obtains the optimized modulation scheme DEPS through offline training of the agent, which can adopt the extended-phase-shift (EPS) modulation scheme and consider the zero-voltage-switching (ZVS) constraints. Thus, the trained agent of the DDPG which likes an implicit function, can provide optimal phase shift angle for the DBSRC in real-time with the minimum current and soft switching performance in the continuous operation range. Compared with the existing EPS modulation schemes using First Harmonic Approximation (FHA), the DEPS modulation scheme has similar operational efficiency and performance of the converter, while also possessing the ability to obtain modulation angles in real-time based on environmental parameters. Finally, PSIM simulation verifies the effectiveness of the proposed optimization scheme.

Real-time harmonics optimization of seven level converter for megawatt scale solar PV-utility integration

This paper presents a new single photovoltaic (PV) array fed cascaded H bridge (CHB) submodule based three-phase 10 MW solar photovoltaic (SPV) plant for medium voltage utility applications. Each submodule comprises of a single PV array, cascaded H bridge cells and line frequency transformers. A 10 MW seven level converter based solar PV plant is realised with four submodules feeding solar PV array power to 33 kV grid. In megawatt scale multilevel converters based configuration, semiconductor switches experience reduction in voltage stress and requirement of high switching frequency for gating for switches is eliminated. Moreover, an efficient single stage MPPT based decoupled controller is implemented with genetic algorithm inspired fundamental frequency switching. GA based optimization technique is used to calculate optimal switching angles in offline mode. Obtained switching angles are incorporated to achieve closed loop optimized decoupled control of SPV system. Lower order harmonics are eliminated and power is fed to grid at enhanced power quality. This large scale PV system is modelled in MATLAB-Simulink and simulated results are validated in real time.

Performance evaluation of coloured filters on PV panels in an outdoor environment

AbstractThis study aims to investigate the effects of colour filters and tilt angles on the electrical output characteristics of solar photovoltaic modules. The experimental set‐up allowed for the evaluation of various combinations of colour filters and tilt angles by using a realistic simulation of solar panel installations. The various light spectrum wavelengths and energy levels were taken into account, keeping in mind any potential impacts on the solar cells' conversion efficiency. The results showed that compared to other filter combinations, the use of red colour filters with a 10% blockage rate and an optimal tilt angle led to a noticeable increase in electrical output. This result emphasises the value of colour filtering and tilt angle selection in raising solar photovoltaic systems' overall performance. When compared to the other filters, the red, orange, and yellow filters stand out due to their outstanding efficiency of around 84.98%, 84.08%, and 83.69%. However, the teal, green, and blue filters exhibit relatively low levels of efficiency of about 69.62%, 67.06%, and 58.52%, respectively. The distinct reaction shown by purple and pink filters, when subjected to tilt angle of 30 degrees, offers a potentially productive direction of enhancing the efficiency of PV panel.

Off-iso Winston-Lutz test on seven linear accelerators.

The aim of this study is to find optimal gantry, collimator, and couch angles for performing single isocenter, multiple target stereotactic radiosurgery (SIMT-SRS). Nineteen angle sets were tested across seven linear accelerators for radiation-isocenter coincidence and off-isocenter coincidence. The off-isocenter Winston-Lutz test was performed to evaluate the accuracy of isocenter alignment for each angle set, and optimal angle sets as well as maximum off-isocenter distance to target for each angle set was determined. The influence of simulated patient weight on off-iso Winston-Lutz test accuracy was also inspected. The SNC MultiMet-WL phantom and MultiMet-WL QA Software v2.1 were used for the direct measurement and analysis of the off-iso Winston-Lutz test (also referred to as Winston-Lutz-Gao test). A two-step method was developed to ensure precise initial placement of the target. Nineteen beams were delivered at 6X energy and 2×2cm field size to each of six targets on the MultiMet Cube with couch kicks at five cardinal angles (90°, 45°, 0°, 315°, and 270°). To reduce imaging uncertainty, only EPID was used in target alignment and test image acquisition. A total of 200Ibs (90.7kg) of weight was also used to mimic patient weight. All tests were performed on both the free table and the weighted table. For two new TrueBeam machines, the maximum offset was within the 1mm tolerance when the off-iso distance is less than 7cm. Two older VitalBeam machines exhibited unfavorable gantry, couch, and collimator (GCC) angle sets: Linac No. 3 at (0,90,0), (0,270,0) and Linac No. 4 at (0,45,45) and (0,90,0). The C-Series Linacs failed in the majority of GCC angle sets, with Linac No. 5 exhibiting a maximum offset of 1.53mm. Four of seven machines show a clear trend that offset increases with off-isocenter distance. Additionally, the IGRT table was less susceptible to the addition of simulated patient weight than the ExactCouch. Among the seven linear accelerators addressed, newer model machines such as the Varian TrueBeam were more precise than older models, especially in comparison to the C-Series Linacs. The newer machines are more suitable for delivering SIMT-SRS procedures in all GCC angle sets, and the results indicate that newer TrueBeams are capable of performing SIMT-SRS procedures at all angle sets for targets of off-iso distances up to 7cm. The trend that offset between the target center and radiation field center increases with off-iso distance, however, does not always hold true across machines. This may be comprised by the EPID's severe off-axis horn effect. Lastly, the IGRT couch was less susceptible to patient weight compared to ExactCouch in the off-isocenter Winston-Lutz test.

Optimizing film mechanical and water contact angle properties via PLA/starch/lecithin concentrations

The optimization of mechanical property and water contact angle of PLA/starch/lecithin film was conducted using response surface methodology. The tensile strength, Young's modulus and water contact angle of PLA/starch/lecithin film ranged from 0.44 ± 0.21–7.18 ± 0.57 MPa, 133.78 ± 33.7–775.57 ± 85.44 MPa and 17.71 ± 1.93–59.41 ± 28 (o), respectively. The amount of PLA and starch significantly impacts tensile strength and Young's modulus. Unlike starch, increasing PLA in the film formulation increases tensile strength and Young's modulus. The PLA-lecithin interaction decreases the film tensile strength and Young's modulus. The film water contact angle is statistically impacted by the PLA/starch interaction and quadratic term of lecithin. The adjusted R-square and p-value of each of the response ANOVA result indicates that the model quite captures the behavior of the responses. The response 2D plots also provide more insight into the variable behavior on the resulting response, making the response surface methodology a tool to design, develop and optimize PLA-based films.

Research on Residential Interior Design and Energy Saving Optimization with Sustainable Low-carbon Development

The escalating crisis of global warming, driven by the emission of greenhouse gases, poses a formidable challenge for humanity as a whole. Notably, the construction industry contributes significantly to the global greenhouse gas inventory. Consequently, prioritizing low-carbon construction assumes paramount importance in mitigating the pervasive impact of the greenhouse effect on a global scale. Such an endeavor stands as a crucial safeguard for ensuring the sustainable development of human civilization. Therefore, from the perspective of low- carbon building design optimization research is an important part of low-carbon building. From the perspective of architectural design, this paper summarizes that low-carbon building design should pay attention to following aspects: reasonable use of natural lighting and natural ventilation, reduce the carbon emission value of building use stage; Taking the transformation project of the former engineering Institute of Southeast University as an example, this paper probes into the effect of design optimization on reducing carbon emissions, and quantitatively studies the relationship between the design optimization of lighting, ventilation and envelope structure materials and the reduction of building carbon emissions. The Angle selection of roof skylight is studied from the Angle of day- lighting optimization, the size and position of facade opening and the strategy of natural ventilation path are studied from the Angle of ventilation optimization. The indoor ventilation further reduces the refrigeration energy consumption, which is 22.1% less than before the renovation, and the roof reduces the heat gain by 22%-32%.e.

Analysis of performance improvement methods for offshore wind turbine blades affected by leading edge erosion

Leading edge erosion (LEE) poses greater challenges to the blade design of offshore wind turbines. This paper analyzes the influence of LEE on blade aerodynamic performance and wind turbine load based on high-power offshore wind turbines through the GH-Bladed computing platform. The study found that LEE severely weakens the blade aerodynamic performance, resulting in a lag in the wind turbine reaching its rated power. LEE expands the range of blade surface flow separation, leading to an increase in blade stall risk and a decrease in wind turbine load stability. The promotion of blade aerodynamic performance will cause an increase in blade force, which will strengthen the load level of both the blade and the wind turbine. The optimization of twist angle is an effective method to avoid the loss of power generation of wind turbines under LEE interference, but it is inevitable to cause a decrease in the load stability of wind turbines. Therefore, when the load safety margin of wind turbines is sufficient, adjusting the twist angle is an efficient technique to improve the blade aerodynamic performance and promote the stability of power output, which provides a novel solution for blade design of high-power offshore wind turbines.

CFD and RSM Assist in Reducing the LPG Consumption of Burners for Agarwood Oil Production in Thailand

ABSTRACT This research aimed to optimize LPG consumption in Thai commercial burners used in agarwood oil production, specifically focusing on the KB-10, S-10, and EB-10 burners. Enhancing burner efficiency is crucial due to rising energy costs and environmental concerns. A dual approach using Response Surface Methodology (RSM) and Computational Fluid Dynamics (CFD) was employed in order to achieve the best burner. Central Composite Design (CCD) within the RSM framework determined the optimal swirl and inclination angles combinations. Modified burners with variant combination angles, as suggested by RSM, were numerically investigated. CFD simulations with Ansys Fluent, utilizing the k-ε turbulence and discrete ordinates (DO) radiation models, provided detailed insights into the combustion and heat transfer processes of those modified burners. The modified burners, SB10–1, SS10–3, and SEB10–7, demonstrated significant improvements. Laboratory and field tests indicated energy savings of 16.15%, 23.74%, and 20.75%, respectively. Statistical analysis confirmed these savings with p-values < .05. The 95% confidence intervals for LPG savings were 31.31 ± 0.8%, 33.42 ± 0.7%, and 31.84 ± 0.6%, corresponding to payback periods of approximately 2.99, 4.21, and 8.95 months. Additionally, CO and NOx emissions were kept below 350 ppm and 100 ppm, respectively. The novelty of this study lies in the combined use of RSM and CFD to optimize burner performance, leading to significant energy savings and emission reductions. These findings highlight the potential of these methods for burner optimization, offering both economic and environmental benefits. This research underscores the importance of integrating advanced modeling techniques to achieve sustainable and cost-effective industrial processes.

Novel feature selection based ANN for optimal solar panels tilt angles prediction in micro grid

Predicting PV system electricity output is necessary for daily operational management and annual power system planning when integrating solar collector-based photovoltaic (PV) stations into micro grids. Tilting the panels at the ideal angle to maximize solar energy capture is necessary to maximize PV station production. This optimal tilt angle (OTA) must be predicted as it is a nonlinear function of the total solar radiation, diffuse solar radiation, and direct solar radiation. This research explores the use of feature selection-based artificial neural networks (ANN) with various machine learning algorithms to predict the OTA for PV systems at specific locations, aiming to maximize PV output in micro grids. The study identifies global solar radiation, diffuse solar radiation, clarity index, and global solar radiation on inclined surfaces as the most critical inputs for predicting OTA, while extraterrestrial radiation is deemed the least significant. Implementing the appropriate input variables significantly enhanced prediction accuracy from 38.59 % to 90.72 %. Among the neural networks evaluated, the Elman neural network demonstrated the greatest improvement.

Simulation analysis and optimization of containerized energy storage battery thermal management system

The air-cooling system is of great significance in the battery thermal management system because of its simple structure and low cost. This study analyses the thermal performance and optimizes the thermal management system of a 1540 kWh containerized energy storage battery system using CFD techniques. The study first explores the effects of different air supply angles on the heat transfer characteristics. Second, the evaluation indexes of heat removal efficiency, air exchange efficiency, temperature and velocity uniformity coefficient are used to select the optimal air supply angle by the Topsis method. Then, the return air vent position is optimized based on the optimal air supply angle, and the optimal solution is obtained. Research indicates that increasing the air supply angle enhances air mixing within the container and simultaneously decreases the battery pack surface temperature. With a 90° air supply angle, the maximum temperature reduces to 33.58 °C, a 19.52 % reduction compared to 30°. The temperature difference across each battery surface also drops by 16.02 % to 3.46 °C. Adjusting the position of the return air vent further improves temperature uniformity and air flow distribution within the battery compartment. When the air supply angle is 90° and the return air vent evenly distributed at Z = 0.85 m next to the fire door, an optimal uniform temperature distribution is achieved. This reduces the maximum surface temperature by 16.47 %, from 36.67 °C to 30.63 °C and decreases the average temperature difference to 3.0 °C, 21.4 % lower. Thus, the present method effectively enhances the performance of the containerized energy storage battery thermal management system.

Investigating Branched Cut-off Wall Effect on Seepage Using Numerical Modelling

In this research, numerical modelling has been conducted to expand on existing research on cut-off walls mainly done by, [2] and [8]. This study is aimed at examining a unique geometric alignment that accommodates ‘branches’ on either side of a vertical 12-metre-deep cut-off wall and investigates the subsequent effect on seepage (discharge) and uplift force within the foundation of the dam. From the study conducted it had been observed that seepage was reduced with the inclusion of these branches whilst the cut-off wall was located at the centre base of a concrete dam. Subsequent testing of altering the branches’ angle presented a further reduction in seepage through the soil strata, with the optimum angle being around the range of 60–70 degrees. Further experimentation had shown that altering the position at two other distinct locations (dam’s heel and toe) has had a significant reduction in seepage with the heel being the most effective at reducing it. Uplift pressure has been evaluated to show that the best position for minimal uplift force is at the heel of the dam.

Optimum Solar Collector's North-South Tilt Angles for Dar es Salaam and their Influence on Energy Collection

Solar collectors may receive significantly more solar radiation if some kind of Sun tracking is utilised. Optimal collector tilt angles, however, depend on the geographic location and other parameters including solar insolation for the site. In this study, daily, monthly, biannual and annual optimum tilt angles are calculated using a tilt angle-latitude relation model. The data are then used to obtain monthly and yearly optimum tilt angles through weighted averages considering the yearly fluctuations in solar radiation. The optimum annual tilt angle for Dar es Salaam is found to be 5.3° northwards, whereas biannual tilt angles due south and north are 10.5° and 18.9°, respectively. Analysis on the energy collection by a north-south tracking solar collector revealed an improvement of about 5% with optimum daily and monthly tilting, 4.3% with biannual tilting and about 0.8% with annual tilting, compared to a fixed horizontal collector. The results from this study provide optimal tilt angles for Sun tracking in Dar es Salaam and significant gain in energy collected by the solar collector may be realized through daily, monthly or biannual tracking of the Sun.

Mechanical properties of lotus petiole bio-inspired structures under quasi-static radial load

The lotus petiole in nature is characterized by its porous structure and high bending resistance. Inspired by this, in this paper, random sampling of lotus petiole was carried out to clarify the porous distribution pattern of lotus petiole in cross section. On this basis, the original structures with 12 and 13 wells (Os-12w, Os-13w) were constructed, and equal mass hollow circular tube (Emhct) was also designed for comparison. Based on the experimentally verified finite element models, Os-12w, Os-13w and Emhct were comparatively analyzed. In addition, comparisons were made with five other bionic circular structures Compared to the rest of the structures, Os-13w performs better in all comprehensive properties. The bending and traction in the core region of the bionic structure caused the surrounding structures to join in the buckling earlier, creating a global crushing trend. More interestingly, further bending and traction in the core region creates a negative Poisson's ratio phenomenon. In addition, the results of the parametric study show that the optimum loading angle of Os-12w is between 60° and 90°, and the proper adjustment of its core cross-section characteristics can improve the mechanical properties of the structure. This study provides some reference for the development of thin-walled porous structures under radial loading conditions.

Gas exchange optimization in aircraft engines using sustainable aviation fuel: A design of experiment and genetic algorithm approach

The poppet valves two-stroke (PV2S) aircraft engine fueled with sustainable aviation fuel is a promising option for general aviation and unmanned aerial vehicle propulsion due to its high power-to-weight ratio, uniform torque output, and flexible valve timings. However, its high-altitude gas exchange performance remains unexplored, presenting new opportunities for optimization through artificial intelligence (AI) technology. This study uses validated 1D + 3D models to evaluate the high-altitude gas exchange performance of PV2S aircraft engines. The valve timings of the PV2S engine exhibit considerable flexibility, thus the Latin hypercube design of experiments (DoE) methodology is employed to fit a response surface model. A genetic algorithm (GA) is applied to iteratively optimize valve timings for varying altitudes. The optimization process reveals that increasing the intake duration while decreasing the exhaust duration and valve overlap angles can significantly enhance high-altitude gas exchange performance. The optimal valve overlap angle emerged as 93 °CA at sea level and 82 °CA at 4000 m altitude. The effects of operating parameters, including engine speed, load, and exhaust back pressure, on the gas exchange process at varying altitudes are further investigated. The higher engine speed increases trapping efficiency but decreases the delivery ratio and charging efficiency at various altitudes. This effect is especially pronounced at elevated altitudes. The increase in exhaust back pressure will significantly reduce the delivery ratio and increase the trapping efficiency. This study demonstrates that integrating DoE with AI algorithms can enhance the high-altitude performance of aircraft engines, serving as a valuable reference for further optimization efforts.

Path planning of humanoid robots on complex terrains using an efficient regression-based chaotic Harris Hawks optimization approach

PurposeOptimal navigation and trajectory planning are in high demand because of the rise in automated systems. This study aims to focus on implementing an intelligent regression-based chaotic Harris Hawk optimization (LR-CHHO) to achieve a globally optimal path free from collisions.Design/methodology/approachThis study removes the drawbacks of the existing HHO model in terms of its exploration and exploitation behaviors. After the threat is encountered, the improved controller is activated. The LR tool, here, avoids the issue related to the sensitivity of the model. The virtual Hawks, as per the HHO technique, are generated and trained to enhance the diversity in Hawks population. The final controller then calculates the optimal turn angle for the humanoid to avoid threats before reaching the goal.FindingsModel showed an overall improvement greater than 4% in the path and 9% in time compared with standard models in Terrains 1 and 2. Regarding energy efficiency, a significant improvement of more than 20% in the hip, 14% in the knee and 30% in the ankle was observed on both even and uneven terrains.Originality/valueThe originality of this study focuses on improving the diversity in the HHO population by introducing the LR-based model to help the humanoids find an optimal path to the goal. Although the basic model lacked an optimal solution because of sensitivity, less diversity, etc., the proposed model helped resolve the issue and achieve an optimal turning angle for the humanoids to trace the optimal path.

Phase Angle as a Predictor of Mortality in Older Patients with Hip Fracture.

The aim of our study is to determine if there is an association between phase angle obtained by bioelectrical impedance analysis (BIA) and mortality in older patients with fragility hip fractures. A prospective study of patients over 65 years old and hospitalized with a diagnosis of hip fracture was conducted. BIA was performed 24 to 48 h after surgery. Mortality was recorded, and the optimal phase angle cut-off value for predicting mortality was determined by using receiver operating characteristic (ROC) curves. A total of 262 patients were included. Of the patients studied, 10 (3.8%), 21 (8%), 39 (14.9%) and 53 (20.2%) died at 1, 3, 6 and 12 months after surgery, respectively. The phase angle cut-off for mortality at 12 months was 4.05° in women and 4.65° in men. A total of 94 patients (35.9%) were considered to have a low phase angle. After adjustment for possible confounders, mortality in patients with a low phase angle was 5.1 times higher at 1 month, 3.1 times higher at 3 months, 2.9 times higher at 6 months, and 2.8 times higher at 12 months. Phase angle is associated with prognosis in patients admitted for hip fracture regardless of age and comorbidities and can be positioned as a prognostic tool for mortality at 1, 3, 6 and 12 months.