Analysis Of Temperature Field Research Articles

MODELLING AND SIMULATION OF NONLINEAR DYNAMIC FLOW FIELD AND TEMPERATURE FIELD OF DEPYROGENATION TUNNEL

Nonlinear dynamics plays a crucial role particularly in equipment validation of preparation production, validation results of which will significantly influence the results and period of drug registration in drug production processes. In this research, the flow field and temperature field simulation, calculation and analysis are creatively carried out in terms of depyrogenation tunnel, a very popular preparation drying-sterilization equipment in pharmaceutical processes with strong dynamic characteristics. After construction of 3D model of this equipment using Catia and mesh generation applying ANSYS, the computational fluid dynamic (CFD) method and verification of irrelevance method are carried out regarding 6.05 million of meshes to identify the flow velocity model and heat transfer model inside the equipment, to further provide methodology for pharmaceutical process validation and to further optimize the design of control methods. After calculation and simulation, the low-velocity vortices of different sizes inside the hood and the drying chamber are identified, which could cause vials to fall down; meanwhile, vials that are farther away from the outlet receives less heat exchange effect, which would shrink the effective sterilization area, indicating an inadequate validation methodology in pharmaceutical processes.

Analysis of Temperature Field of Very Large Aperture Radio Telescope

With the increase of antenna aperture and frequency, the influence of solar heat on its performance becomes more and more serious. In this paper, the thermal model of the 110 m aperture radio telescope to be built in Xinjiang is established to study its temperature field characteristics on the summer solstice. The results are as follows: during the day, the highest temperature of the main reflector can reach 42.86∘C, which appears at 14 o’clock, and the temperature of the legs also reaches the peak of 41.74∘C at the same time. The horizontal temperature difference of the back frame will exceed 1∘C at 5, 18, and 19.5 o’clock, the antenna pointing performance will be greatly affected. The temperature field at night is also not uniform, and the temperature difference of the pitching structure is significantly higher than that of other components, with the maximum temperature difference of 6.42∘C. Through the method of numerical simulation and test, it is proved that the wall thickness difference of components is the main reason for the large temperature difference at night.

Transient analysis of temperature field and fission gas about the arc plate fuel element

Obtaining the temperature field and fission gas release of fuel elements are crucial to the study on fuel behaviors and ensure the safety of elements. In order to enhance fuel efficiency, providing a design idea to make the fast reactor with high flux and multi-function, we have designed a core of the lead-based fast reactor with arc plate fuel elements. Based on above, a transient performance analysis program of arc plate fuel elements (TPAPAFE) was developed in this paper, for analyzing the thermal and fission gas module of arc plate fuel element by calculating transient variation in the maximum pellet temperature, internal and external coolant outlet temperature, and fission gas release share. The modular verification was done by comparing the results of TPAPAFE with others. Besides, the result of the arc plate fuel analyzed by TPAPAFE shows that the code is feasible and rational, and the single arc plate is so thin that coolant outlet temperatures on both sides of the plate are almost the same. Meanwhile, the error in temperature data between TPAPAFE and the steady-state program is only 5%. Furthermore, fission gas release fraction increased linearly with pellet temperature and bubble growth.

Experimental and numerical study of the three-dimensional temperature field in the arch ribs of the reinforced concrete ribbed arch bridge during construction

The unique structural design of an arch ring featuring varying inclination angles for individual segments causes variations in the longitudinal distribution of the temperature field d along the arch axis. This study aims to enhance the understanding of temperature fields in reinforced concrete (RC) arch bridges with diverse arch ring structural configurations during their construction phases. A comprehensive investigation into the three-dimensional distribution pattern of solar-induced temperature fields within arch ribs during the construction of RC ribbed arch bridges was conducted. A field test specifically measuring the temperature distribution across arch rib cross-sections was conducted on-site, involving an RC arch bridge constructed using the cable-stayed cantilever cast in situ method. Analyzing the monitored on-site temperature data revealed the distribution characteristics of temperature fields at the arch foot cross-section under solar radiation. By comparing these findings with international standards, a vertical temperature gradient fitting model for arch rib cross-sections under solar radiation was formulated. Drawing upon meteorological records and solar radiation principles, an adaptive numerical simulation finite element model was developed to depict the temperature field within an arch rib section. This model was rigorously verified. Subsequently, a comprehensive analysis of the three-dimensional temperature field of the arch rib under solar radiation was performed. Additionally, a three-dimensional temperature gradient fitting model was proposed, accounting for the longitudinal inclination of the bridge.

Temperature field analysis and cooling structure optimization of permanent magnet linear synchronous motor

A water-cooled permanent magnet linear synchronous motor was designed, and the investigation focused on the temperature distribution of motor and the optimization of the cooling structure to address its electromagnetic thermal effects. Firstly, the electromagnetic model of the motor was employed to calculate losses using finite element analysis. Subsequently, the motor's temperature distribution under various operating conditions was determined through electromagnetic-thermal coupling analysis, with prototype measurements validating the predicted outcomes. Secondly, the study placed emphasis on the impact of different water-cooled structure parameters on the motor's cooling performance, resulting in a 69 % reduction in the maximum temperature of the motor module after the cooling system was applied. Building on this, cooling structure parameters underwent optimization and design via the response surface optimization method, which achieved a reduction of 0.617 K in the motor's maximum temperature. The analysis findings revealed a substantial improvement in the motor's thrust performance by a factor of 3.08 when the water flow rate reached 1 m/s. This research can serve as a fundamental reference for the design of water cooling structures for permanent magnet linear synchronous motors.

Study on the convective heat exchange coefficient of concrete surface considering the surface roughness

A heat exchange experiment of concrete surface under different roughness conditions was conducted, and the convective heat exchange coefficient model of concrete surface influenced by many factors was deduced and developed. The model comprehensively considers the effects of concrete surface roughness, wind speed, air humidity and thermal conductivity on the surface heat exchange performance. We obtained the model parameters from experimental data, which captured the convection heat transfer process under controlled laboratory conditions. The comparison between the calculation result and the measurement data is good enough, and prove the selection value of the model parameters are very good. The new convective heat exchange model can better reflect the heat exchange of the concrete structure surface under complex boundary conditions, provide support for more accurate simulation analysis of concrete temperature field, and provide the possibility for better calculation of concrete temperature stress and control of temperature cracks.

Relationship between cross-sectional plane and corresponding morphology in an immiscible alloy powder with core-deviated structure

Immiscible alloy powders with core/shell structure have recently garnered considerable interest due to their excellent industrial performance. However, a frequently observed yet often overlooked feature is the presence of core-deviated structure in various cross-sectional planes of the powder. To date, limited research has been conducted on this structure and its origin, leaving the formation mechanism unclear. Gaining a comprehensive understanding of this mechanism is crucial for advancements in powder materials research. In this study, we first analyzed the solidification microstructures of Fe-68 wt.%Sn alloy powders, followed by a numerical analysis of airflow and internal temperature fields within a powder during the free-falling process. Our findings revealed that the average airflow velocity on the windward side is faster than that on the leeward side, causing the highest temperature point within the powder to shift towards the leeward side over time. This phenomenon is fundamentally linked to the formation of the core-deviated structure. Furthermore, we explored the relationship between cross-sectional planes and potential microstructures, demonstrating that the final observed structures are strongly influenced by the position and orientation of the cross-sectional plane. Additionally, the core deviation distance was theoretically predicted and found to be consistent with experimental results in Fe-68 wt.%Sn powders. This research provides valuable insights into the actual solidification process of immiscible alloy powders and contributes to the development of specialized structural materials.

Exploring flow boiling characteristics on surfaces with various micro-pillars using the lattice Boltzmann method

In this study, the lattice Boltzmann method is utilized to simulate flow boiling within a microchannel featuring a micro-pillar surface. This investigation aims to explore the impacts of micro-pillar shape and quantity on the flow boiling characteristics across various superheats and Reynolds numbers (Re). A systematic examination is conducted on three types of micro-pillars, five quantities of micro-pillars, four Re values, and 18 superheat levels. The mechanisms contributing to enhanced heat transfer in flow boiling are elucidated through a comprehensive analysis of bubble dynamics, temperature and velocity fields, local and transient heat fluxes, and boiling curves. Moreover, the critical heat fluxes (CHF) of all surfaces are evaluated to identify the superior micro-pillar configurations. The findings revealed that microchannels with micro-pillar surfaces induce more vortices compared to those with smooth surfaces, attributable to the combined effects of bubble dynamics and micro-pillars. Bubble patterns and boiling curves demonstrated the significant impact of micro-pillar geometrical shapes on the boiling regime and heat transfer performance. As flow boiling progressed, an increase in micro-pillar quantity and Re can mitigate the fluctuation and decline rate in transient heat flux, respectively. Among the three types of micro-pillar surfaces, the circular shape exhibited the highest flow boiling performance, followed by the triangular and rectangular shapes. For all surfaces, the CHF increased with Re, and each micro-pillar type displayed an optimal quantity for achieving maximum CHF, with the highest increase reaching 45.2%. These findings are crucial for optimizing microchannel designs to enhance flow boiling heat transfer efficiency.

Determination of fan height based on FDM nozzle temperature field analysis—an example of babbitt alloys

In this paper, the phenomenon of nozzle clogging or drooling droplets in the process of FDM metal 3D printing of tin-based Babbitt alloys was evaluated by simulation to assess the effects of different heights of cooling fans on the printer’s nozzle cooling module, and the optimal height of the fans was determined. Based on the thermal analysis results, a thermodynamic coupling analysis was carried out to analyze the thermodynamic changes of the nozzle at a given temperature. Finally, the printing trials of tin-based Babbitt alloy were carried out using self-developed forming equipment to verify the accuracy of the theory. The results show that the print quality can be effectively improved by controlling the heat dissipation module of the printer nozzle. The printed material exhibited a uniform and fine microstructure in the 3D printing trials of tin-based Babbitt alloy.

The effects of laser line energy on welding strength of PASF/PC using magnesium zinc alloy powders as absorbents in laser transmission welding

The metal powder absorbents have the advantage of fabricating clean and high-strength joints in the process of laser transmission welding dissimilar transparent thermoplastics. However, the joining behavior between metal powders and thermoplastics is vague. Herein, polyarylsulfone (PASF) and polycarbonate (PC) are selected as model materials to investigate the joining behavior using magnesium zinc alloy (MZA) powders at different laser line energies. The shear force test was performed to reveal the effect of laser line energy on the welding. The µ-CT images reveal the evaluation of welding strength is attributed to the specific joint morphology. The multi-scale morphology characterization shows that the fractured surface height increases with increasing the laser line energy. The voids between MZA powders and resins increase the risks of interface failure, and the bubbles in the resins increase the risks of cohesion failure. The effects of laser line energy on the joint characteristics are elaborated based on the thermo-physical property test and transient temperature field analysis. The above results indicate the optimized welding temperature locates the melting temperature of PASF, because of the good fusion of PASF and less decomposition of PC. The study can provide a guideline for choosing proper process parameters when choosing metal powders as laser absorbents in welding dissimilar transparent thermoplastics.

Analysis of Temperature Field of Silicone Heating Plate based on COMSOL

Background: In the manufacturing process of lithium batteries for new energy vehicles, silica gel plates shall be used as heating and thermal insulation. This paper takes four groups of silica gel heating plates with different specifications as the research object to predict the temperature distribution of silica gel plates and provide theoretical references for the manufacturing engineering of silica gel heating plates. Objective: Combined with the heat transfer theory, the temperature distribution of silica gel heating plate is predicted by simulation calculation, and the feasibility of this method is verified by experiments, which provide references for the manufacturing engineering of silica gel heating plate. Methods: This article takes four groups of silica gel plates with different specifications as the research objects, and 30 temperature measurement points are collected. The simulation results are compared with the experimental results to verify the method’s feasibility. Results: The average error between the experimental and simulation results was ± 2.6°C, which was in line with the expected effect of silica gel plates. This paper’s research process and method can provide theoretical references for the manufacturing engineering of silica gel heating plates. Conclusion: Taking the silica gel heating plate provided by the factory as the research object, according to the heat transfer theory, the thermal conductivity equation of the silica gel plate was established, which provided a theoretical model for simulation analysis. The experimental results show that the average error between the simulation and experimental results is ±2.6°C, which is in line with the empirical expectation, and the method is feasible. This paper’s research process and practice can provide theoretical reference for the manufacturing engineering of silica gel heating plate.

Numerical calculation and analysis of temperature field in ultrasonic welding of polypropylene dialyzer

Ultrasonic plastic welding is widely used in the bonding process of medical device accessories. In this paper, a thermo-force indirect coupling finite element analysis model was established in the ultrasonic plastic welding process between the blood cap and the shell of polypropylene (PP) dialyzer. The temperature field distribution between the blood cap and the shell was simulated and analyzed by using finite element analysis software, and the influence of welding process parameters on the temperature field was studied. The results show that: by changing the ultrasonic amplitude parameters, welding time parameters, initial pressure, etc., the longer the ultrasonic welding time, the temperature of the welding area will increase. In order to ensure the quality of the dialyzer, it should be controlled within 0.8-1 seconds. The increase of ultrasonic amplitude will make the welding temperature continue to rise, and in order to avoid poor welding, the amplitude should not exceed 120 ?m. The initial pressure has little effect on the temperature field.

基于ANSYS的离合器压盘热变形与模态优化分析

基于ANSYS的离合器压盘热变形与模态优化分析

СОВЕРШЕНСТВОВАНИЕ ТЕХНОЛОГИИ ДИАГНОСТИРОВАНИЯ ОПОРНЫХ УЗЛОВ ТРАНСМИССИИ АВТОМОБИЛЯ КАМАЗ-55111

The paper presents trends in the development of automatic diagnostics systems for mechanical transmission units. (Research purpose) The research purpose is substantiating the technology of automatic identifying the pre-failure condition of transmission units. (Materials and methods) The supporting components of the KamAZ-55111 transmission with rolling bearings 50412 and 53610 were chosen as the research material. The analysis of existing methods of labor intensity, methods for calculating machine parts, reference information on bearings, finite element analysis of temperature fields and regression analysis were used. (Results and discussion) The characteristics of the indicators of the transmission support units (rolling bearings) were described, methods of their diagnosis were considered. The forces acting on the bearings on the secondary and intermediate shafts of the KamAZ-55111 car were calculated. The design, technological and operational parameters were used to calculate the temperature in the friction zone. In order to improve the diagnostic technology, temperature fields were simulated using the APM FEM CAD Compass 3D application. A device for automatic temperature measurement in the friction zone and a sensor for temperature measurement have been developed. (Conclusions) The reliability of the transmission support units of agricultural machinery is affected by the working conditions. It was established that the most effective method of diagnosing the complexity of the transmission is the method of thermodiagnostics. Analysis of the temperature in the friction zone of bearings 50412 and 53610 from first to fourth gear showed a decrease in temperature. The study of temperature field maps made it possible to establish the relationship between the temperatures in the friction zone and in the control zone of bearings 50412 and 53610. A recorder for automatic monitoring of the technical condition of the nodes has been developed and tested.

Development of models and analysis of temperature fields of new energy-saving enclosing structures with an air layer

The author of the article propose new models of energy-saving envelope structures with air interlayers. To calculate the temperature fields in the enclosing structures they used the finite element modeling method in ANSYS environment. The authors analyzed the temperature fields at different variants of the outdoor temperature index. To calculate the temperature field in the envelope was used finite element model of the envelope, in which the influence of the ventilated air layer is replaced by the Convection type boundary condition with the temperature value. The result of the study is the analysis of temperature fields of new models of enclosures in different variants. So when analyzing the values of thermal resistance of traditional (scheme-1) and developed envelope structures (schemes 2-4) it was found that the thermal resistance of scheme-2 relative to the traditional scheme-1 value of thermal resistance at minimum temperature is 6.2 % higher. The authors also calculated by analogy the thermal resistance index at maximum temperature (4.5 %), at five days (5.8 %) and for the month of April (5.7 %). The analysis showed that scheme-2 is the most efficient of the new envelope schemes considered. In the comparative analysis of schemes - 3,4 with traditional scheme-1, the value of thermal resistance showed a negative effect. The authors determined that the temperature field is insignificantly different when using horizontal and vertical closed channels. The developed new energy-saving designs of external enclosure with air layer can be used in the design and construction of buildings, as well as in the teaching of relevant disciplines in universities.

Turbulence structure of the Rayleigh–Bénard convection using liquid CO2 as working fluid

We studied the evolution of flow structures and large-scale circulations (LSC) in Rayleigh–Bénard convection (RBC) using liquid carbon dioxide as the working medium. In this experiment, a transparent sapphire pressure vessel with observable internal flow was designed, and different temperature differences were applied between the upper and the lower surfaces of the fluid to obtain different Rayleigh numbers (Ra). We employed proper orthogonal decomposition and reconstruction to extract internal flow structures from the shadowgraphy images. We used optical flow techniques to acquire the velocity field of the flow, and we reconstructed the temperature field inside the supercritical fluid using the relationship between shadowgraphy images and refractive index. It is clearly observed that the RBC begins to produce different flow structures under a small temperature difference of 0.4 °C. As the number of Ra increases, the number and the speed of plumes increase, and the morphology of plumes gradually becomes elongated. When Ra exceeds a certain critical value, an LSC structure appears in the flow field, and the plumes translate laterally with the large-scale circulation, and the disorder of the vortex structure in the central flow region increases significantly. Three typical flow structures were observed: (1) single plume, (2) thermal boundary layer traveling waves, and (3) Rayleigh–Taylor instability waves. We believe that the traveling wave structure is the precursor to the single plume. The temperature field analysis of the three structures was carried out, and the velocity of the typical plume was calculated by the optical flow method. It was found that LSC transitioned from oval to square shape with the increase in Ra, and the internal plume Reynolds number slowly increased with the increase in Ra. By the in-depth study of the thermal turbulence characteristics and the coherent structure evolution law of RBC, this paper provides experimental support for revealing the mechanism of enhanced heat transfer in energy system with a liquid CO2 working fluid.

2D temperature field analysis of asphalt pavements with three different types of subgrade structures

To explore the temperature distribution in width and depth of asphalt pavements with three different subgrade types, a numerical model is established. Based on actual meteorological data, the lateral temperature differences (LTDs) along the depth direction of pavement layers were analyzed under diurnal periodic thermal boundary conditions. Results reveal that the maximum LTD on the surface of a part-cut part-fill subgrade roadbed structure, as represented by a mountainous road, can reach 6.3 °C and 10.8 °C during winter and summer, respectively. The LTDs vary periodically with the boundary conditions. The LTDs on the road surface with high solar radiation in summer are 2.6–7.6 °C higher than those in winter. The influence ranges of the LTDs along the width direction of the road in winter and summer are 0–300 mm and 0–350 mm, respectively. This study provides a more precise method for studying the temperature field of road structures, which is helpful in analysing the pavement damage caused by thermal stress, etc. It also provides the necessary reference for the practical implementation of new technologies in the fields of asphalt pavement thermal energy storage systems and asphalt pavement temperature difference power generation.

Design and temperature field analysis of conical outer rotor hub motor

Design and temperature field analysis of conical outer rotor hub motor

Optimization of rotational oil-spray-cooling structure and temperature field analysis of PMSM in vehicle

The heat dissipation of the permanent magnet synchronous motor (PMSM) of an electric vehicle is always worthy of attention, and the design of the cooling system of the PMSM is very important. The rotor rotational oil-spray-cooling structure is widely used in PMSM with hairpin winding. The oil enters from one side of the hollow shaft and is sprayed from the outlets of the front and rear, respectively, which realizes the cooling of the winding at both ends. However, the flow difference on both sides of the shaft will cause the problem of uneven cooling of the winding and the issue of local overheating of the motor. Therefore, the hollow shaft structure needs to be optimized. A 120 kW oil-cooled motor is analyzed as an example in this paper. The flow field distribution during the rotation of the rotor and the reasons for the uneven shunt are analyzed. And the structural parameters of the hollow shaft are optimized by using the Taguchi method and the response surface method. It was found that the new shaft structure can better realize the shunt and reduce the winding and rotor temperature. It provides a guide for the design of the rotational oil-spray-cooling structure of the oil-cooling PMSM.

Water cooling structure design and temperature field analysis of permanent magnet synchronous motor for underwater unmanned vehicle

Unmanned underwater vehicles (UUVs) have extremely harsh cooling conditions for permanent magnet synchronous motor (PMSM) due to global sealing and compact space, and an efficient heat dissipation system is essential for the safety and operational reliability of PMSM. Currently, with the introduction of seawater and the addition of heat exchanger, liquid reservoir are typically used for open-circuit heat dissipation, which not only adds weight, but seriously affects the flow characteristics of the UUV. In this paper, a novel dual channel water cooling structure is designed to achieve internal circulating heat dissipation without additional auxiliary devices. The temperature field of the PMSM with different water cooling structures is solved by Computational Fluid Dynamics (CFD) under rated operating conditions. The results show that the cooling efficiency of water cooling structures is more affected by low flow rates, accompanied by increasing the flow rate from 0.5 L/min to 24 L/min, the cooling performance is enhanced, but does not entirely obey a strict linear variation. Furthermore, at a flow rate of 6 L/min, the dual spiral water cooling structure performs the best heat dissipation, the maximum operating temperature of the PMSM is reduced by 51.72 K, the maximum temperature rise suppression rate reaches 53.02 %, and the minimum differential pressure of 10.18 kPa.