Effective Heat Dissipation Research Articles

Optimization design of heat dissipation scheme for submarine data center based on analytic hierarchy process

Aiming at the problem of heat dissipation optimization design of submarine data center, firstly, the placement mode of server is designed, and on this basis, the heat generation power of server is analyzed by Newton cooling method of convective heat transfer to determine its feasibility. Secondly, based on the relationship between fluid velocity and pressure and the relationship between fluid velocity and heat dissipation through the container surface, the container structure design and its placement direction are clarified. Then, the optimal container shell material is determined by using multi-attribute decision-making model and analytic hierarchy process. Finally, the quadratic composite function of shell cost and seawater depth with respect to shell thickness is constructed to calculate the appropriate seawater depth. According to the research, considering the structure, placement method, heat dissipation effect and seawater temperature of the container, on the basis that a single container shell can be placed with up to 609 servers, Maraging 300 Steel is selected as the most suitable container shell material.

Effect of selective reinforcement on heat dissipation of 3D-printed poly lactic acid

Additive Manufacturing (AM) represents a sustainable means of production, reducing the need for energy and resources and thus creating eco-friendly products. Homogeneous composites based on metal, polymer, and ceramic are currently used to meet the requirements of the end product. The current investigation attempts to identify functional needs and selective reinforcing with appropriate materials. The effectiveness of heat dissipation, one of the prime requirements in many applications, in metal-integrated polymer systems is assessed using simple representative samples. Representative parts are constructed using material extrusion processing with biodegradable Polylactic Acid (PLA) parts. Given its superior thermal conductivity for selective reinforcement, aluminium (Al) is chosen as the secondary material. The dimensional accuracy of the printed parts is fine-tuned using the different layer parameters to ensure the required interface clearances. A constant heat supply is provided thus to understand the influence of metal reinforcement in interaction with the polymer at the interface. The temperature is measured through the volume to record the heat conduction and dissipation. The metal-polymer sample with the interference fit is found to have the best heat dissipation compared to other alternative geometries. Either an insulating void or the absence of metal-polymer contact reduces the heat dissipation efficiency.

Joule Heating and Viscous Dissipation Effects on a Stretching/Shrinking Cannel Filled by Micropolar Hybrid Nanofluid in Presence Thermal/Solar Radiation

The main goal for this research is to investigate the effect of two composed hybrid nanoparticle materials in heat transfer with account several parameters and in two cases. In addition, exploring how the micropolar hybrid nanofluid (Cu–TiO2) behaves in a shrinking and expansion of the channel. The model considers external factors such as magnetic fields, heat radiation, and solar radiation. The boundary layer approach has been utilized to create transformations that pout the equations of the system in the dimensionless form. The shooting method has been combined with the fourth-order Runge-Kutta-Gill to numerically solve the modified ordinary differential equations. The impacts of the nanoparticles transport on the heat transfer and fluid flow are addressed, and the results are compared to the case of pure water. The velocity, isotherms, angular-velocity, and concentration distributions, are given in tables or graphs. It was found that the effect of heat on the hybrid nanofluids is directly proportional to its velocity and angular velocity. For mass fraction of the two nanofluids φ1 and φ2, the velocity profile f′(η) has a comparable influence for both hybrid nanofluid and nanofluid. The larger quantity of the factors φ1, φ2, M and Q enhance the temperature. For M, φ1 and φ2, the angular velocity profile g(η) has a comparable influence for both hybrid and magnetic parameter. The absorption parameter storing the radiation energy and augmentation of the solar irradiance immersion capacity leads to a greater heat transfer.

Effective Heat Dissipation for Prismatic Lithium-ion Battery by Fluorinated Liquid Immersion Cooling Approach

ABSTRACT In this study, experiments were performed to investigate the cooling effect of liquid immersion cooling based on SF33 for 8 Ah prismatic lithium-ion battery. First, the cell temperature variations under high C rates discharging with natural convection and liquid immersion cooling were compared. The results reveal that liquid immersion cooling has good cooling performance and can limit the maximum temperature of the cell to be below 33.25°C and 35°C even under ultra-fast discharging for 5C and 8C. Then, the effects of cell spacing and liquid filling levels were explored. The cell spacing has less effect on the cooling performance. Meanwhile, the influence of liquid filling level on the cell temperature and temperature uniformity is found to be significant. Finally, the two-phase heat transfer phenomenon of liquid immersion cooling was observed and recorded to investigate the mechanisms for the shifting from single phase natural convection to two-phase boiling heat transfer.

Unsteady mixed convective MHD boundary stagnation point nanofluid flow with multi-slip effects, variable wall temperature and porosity phenomenon

This research highlights the physical significance of nanoparticle in magnetohydrodynamics (MHD) stagnation point flow (SPF) over a stretchable surface with porosity effect and boundary slip phenomenon. The nanoliquid and its advanced thermal activity are shown extra auspicious results when the flow is considered over a permeable (porous) medium. In addition, the nanoparticles of radius size play an important role in the thermal performance of nanofluid. In this work, copper is accounted as a nanoparticle and water as a base fluid. Nanomanufacturing, surface engineering, coatings, nanofabrication and tribology are some of the important and special mechanical characteristics of nanoparticles [D. Guo, G. Xie and J. Luo, J. Phys. D, Appl. Phys. 47, 013001 (2014)]. The flow is electrically conducted in the presence of applied magnetic field. Mixed convection, Joule heating and viscous dissipation effects are accounted in the mathematical modeling. Appropriate similarity variables are used to convert the couple governing system of PDEs into ordinary ones and results are computed through bvp4c via shooting concept. From the obtained results, it is divulged that the velocity field increases against higher estimations of unsteady parameter, while it declines versus larger magnetic parameter and radius of nanoparticles. The engineering interest like skin friction and Nusselt number is mathematically calculated and results are computed in a tabular form, and their obtained outcomes show that the magnitude of skin friction rises against unsteadiness parameter and radius of nanoparticles. This study is an extended work of [Verma et al. Chem. Eng. J. Adv. 12, 100366 (2022)] with some extra flow assumptions like MHD, SPF, Joule heating, heat generation/absorption and viscous dissipation. Obtained results are compared with [Grubka and Bobba J. Heat Transf. 107, 248 (1985)], Verma et al. [Chem. Eng. J. Adv. 12, 100366 (2022)] and [Elbashbeshy and Emam Therm. Sci. 15, 477 (2011)] found 100% accuracy with them. The most important result of the conducted study is that the skin friction coefficient immensely augments subject to larger estimations of radius of nanoparticles when permeability of porosity is less.

Heat Transfer Enhancement of Microchannel with Jets and Ribs

In this paper, we propose a new microchannel heat sink with ribs and jets, which can not only increase the heat transfer performance but also improve the fluid flow in the microchannel. The effects of different shapes of ribs and inlet aspect ratios on the performance evaluation criteria at various Reynolds numbers are discussed. At an inlet Reynolds number of 3000, the maximum temperature of the modified microchannel heat sink is 8.78% lower than that of the smooth microchannel, and the performance evaluation criteria is increased by 0.94. Under the same conditions, the bottom plate temperature difference of the hydrofoil rib microchannel jets is 3.4% lower than that of the cylindrical rib microchannel jets; and the triangular-shaped ribs increase the heat transfer and cause greater pressure loss penalty due to the formation of a larger swirl zone in the back area. The jet inlet parameters can effectively improve the heat transfer coefficient of the microchannel. In terms of the heat transfer capability and the uniformity of the bottom plate temperature, the hydrofoil rib microchannel with jets has the best heat dissipation effect when the jet inlet parameter is .

Viscous dissipation and Joule heating effects on hydro-thermal power law nanofluid through annular duct

This study presents a mathematical model along with numerical simulation to investigate the viscous dissipation and Joule heating effects on electrically conducting magnetohydrodynamics (MHD) forced convection non-Newtonian power law nanofluid flow through annular sector duct. Hydro-thermal power law nanofluid flow through annular sector duct is not investigated in the presence of Joule heating and viscous dissipation effects. The consideration of Joule heating and viscous dissipation effects makes it very much novel in its own right. The main objective of this work is to explore the Joule heating and viscous dissipation effects on hydro-thermal power law nanofluid. Both Copper, Cu/Titanium oxide, TiO2 nanoparticles with base fluid water have been taken as a power law model. Numerically simulation is carried out for viscous, incompressible and steady laminar fully developed fluid flow with constant properties, by using the finite volume method (FVM) and strongly implicit procedure (SIP). It has been observed that viscous dissipation effect on temperature profiles is enhanced in the absence of magnetic field/at lower value of Ha, however, when nanoparticles’ concentration is increased, the effect of magnetic field slightly decreases. Furthermore, by adding Cu nanoparticles from 0% to 5%, we observe the increment in average Nusselt number, Nu up to 16.01% and 16.07% in pseudo-plastic and dilatant fluids, respectively, at [Formula: see text].

A compact LWIR borescope sensor for 2D engine component surface temperature measurement

A compact long-wavelength infrared (LWIR) borescope imaging sensor operating in the wavelength range of 8–14 μm is designed and developed for non-contact two-dimensional (2D) surface temperature measurements in gas-turbine engines. The LWIR detection minimizes optical interferences from hot combustion gases and soot (emission within UV–mid IR region). Using simulations, the system is optimized for improving the signal collection efficiency and minimize image aberrations. The LWIR borescope probe is shielded by the custom-build compact water-cooled probe housing (outer diamter (OD) 19 mm, inner diameter (ID) 10 mm), which can sustain flame temperature up to 2400 K at a pressure of 50 bar. It facilitates long-term optical diagnostics inside the actual high-pressure combustion facilities where extreme thermal acoustic perturbation and intense heat fluxes are encountered. The design, construction, and characterization of the LWIR borescope sensor are discussed in detail. We present the 2D surface temperature measurements of a V-gutter bluff-body with simple nitrogen gas cooling in a laboratory testbed. The results indicate the sensor’s ability to accurately measure surface temperature with low background noise and to track transient cooling effect. The water-cooled probe housing was tested to verify the effectiveness of fast heat dissipation in high-temperature combustion environment to avoid unwanted thermal signals from the LWIR probe window. The developed LWIR sensor suite has promising applications in surface temperature measurements of engine components. The findings of this study may aid propulsion system engineers and researchers in designing thermal management systems and optimizing operation.

Graphene/Polyolefin Elastomer Films as Thermal Interface Materials with High Thermal Conductivity, Flexibility, and Good Adhesion

Heat dissipation has become a central issue for the development of the microelectronic industry. Thermal interface materials (TIMs) have been widely applied to electron component cooling, which is used to bond the heat spreader and the chip together. Most research on TIMs has only dealt with thermal conductivity enhancement. However, the mechanical properties and adhesion of TIMs are indispensable for practical applications, as well as postcleaning to remove TIMs. A graphene nanosheet/polyolefin elastomer (GNP/POE) film was designed and prepared by a facile method, in which the heat conduction paths were efficiently constructed, and the good mechanical properties of POE were reserved. The thermal conductivity of as-prepared GNP/POE film can reach 1.07 W m–1 K–1 at an extremely low filler loading of 0.62 wt %. Furthermore, the tensile strength, elongation at break, and adhesion of the prepared GNP/POE film are as good as those of commercial TIM productions. The prepared GNP/POE film can be used as TIMs for chip cooling and exhibits a good heat dissipation effect. Additionally, the prepared GNP/POE film can be peeled off from the chip without residue, after the chip has finished running, which is significant for practical production. This work provides valuable information and insight into the design and fabrication of TIMs in the future.

Effects of Pulse Interval on Forming Process in Wire Arc Metal Additive Manufacturing Using Pulsed Arc Plasma.

To overcome the material processing challenges induced by high levels of heat input in wire arc additive manufacturing (WAAM), an innovative WAAM method using pulsed arc plasma (PAP-WAAM), was developed by the authors in the previous study. In this method, the PAP generated by the pulsed voltage was used as the heat source. The pulse interval can be defined as the time interval between adjacent pulse voltages, which determines the ignition time and frequency of the arc plasma, thus influencing the forming process. However, the effect of pulse interval on the forming process has not yet been revealed. Here, the effects of pulse interval on forming process during the PAP-WAAM of Ti6Al4V, including thermal behavior, arc plasma characteristics, and metal transfer process, were investigated by experiments and simulation. The results exhibited that the interpass temperature and maximum peak temperature decrease with increasing pulse interval at the same arc plasma power, indicating an alleviation of heat accumulation along the building direction. As the pulse interval increased, the ignition mode of the arc plasma changed from ignition between the tungsten electrode and the previously deposited layer to ignition between the tungsten electrode and filler wire, which increased the proportion of discharge energy allocated to the filler wire, thus reducing the overall heat input required for material deposition. When the pulse interval was 300 and 400 ms, only the uninterrupted bridging transfer mode was observed during the deposition process. The uninterrupted bridging transfer is considered to contribute to forming a smooth and consistent layer appearance. In addition, longer pulse intervals resulted in less surface oxidation, narrower wall thickness, and better macrostructure, attributed to reduced heat input and improved effective heat dissipation. This research reveals the effect of pulse interval on forming process during PAP-WAAM, which benefits the fabrication of desirable metal parts.

Wide range temperature thermal performance of power battery module with double-sided thermoelectric device system with high energy efficiency

In this work, a high energy efficiency double-sided thermoelectric device system for wide range temperature control of cylindrical battery modules is proposed. The heat dissipation and temperature control effects of the double-sided TED device are first evaluated by the experiment and then the cooling and heating performances of TED are analyzed using analytical models. The optimal current is 8.22 A at ambient temperature from −20 °C to 40 °C to balance thermal performances and efficiencies. Experimental research shows that the double-sided TED cooling system reduced the maximum temperature by 35.6 ∼ 15.3 °C, under the heating power of 3 ∼ 5 W for battery cell, which is superior to the pure liquid cooling system. Meanwhile, the maximum temperature and temperature difference of the battery module remain within 25.0 °C and 4.7 °C, respectively, with the battery cell power of 5 W. The two-way switching between cooling and heating of the battery module is realized by changing the direction of the TED current. In the heating mode, the heating efficiency is always greater than 1.24, which is superior to other external heating techniques. Battery temperature fluctuation was well minimized by introducing a temperature controller. This research demonstrates the effectiveness of TED integrated thermal management system for battery modules.

A Comprehensive Study on the Effect of Inhomogeneous Heat Dissipation on Battery Electrochemical Performance

In this paper, the unbalanced discharge of lithium-ion battery module caused by heat dissipation is studied. The battery pack is composed of 12 batteries, which are divided into four modules in series, and three batteries in each module are in parallel. The three-dimensional electrochemical-thermal model of a single battery and a battery pack is established by the polynomial approximation pseudo-two-dimensional (PP2D) method in ANSYS fluent 16.0, and the correctness of the model is verified by simulation and experiment. On this basis, the non-uniform temperature distribution and the coupling relationship between electrical parameters and electrochemical parameters in the battery pack under inhomogeneous heat dissipation were studied. The mechanism of how the temperature difference affects the distribution of current and state of charge (SOC) is also given. According to the research results, the control of the average temperature of the battery pack and the control of temperature difference are incompatible and need to be traded off. Enhanced cooling can reduce the average temperature, but it produces a large temperature gradient, resulting in a greater internal temperature difference of the battery pack. The large temperature difference enlarges the difference of the branch current and aggravates the unevenness of SOC in the battery pack. In addition, the temperature difference most suitable for SOC uniformity is not the traditional 5 °C but increases with the increase of the ambient temperature and the cooling medium temperature.

Parametric FE model for the thermal and hydraulic optimization of a Plasma Facing Component equipped with sacrificial lattice armours for First Wall limiter application in EU-DEMO fusion reactor

In EU DEMO reactor, components exposed to burning plasma are subject to extreme conditions due to short and extremely strong thermal transients, which impact their lifetime and functional integrity. Due to this energy, surface vaporization, melting and resolidification may lead to excessive degradation and frequent extraordinary maintenance. For this reason, in view of DEMO and future reactors, one of the most challenging aspects of fusion reactor technology is to devise FW (First Wall) sacrificial limiters that will prevent excessive damage of the otherwise un-shadowed FW modules during extreme plasma transients. Rather than dense armours, W-lattice structures can contribute to this purpose, since they can be optimized to have a thermal conductivity that ensures, at steady state, effective heat dissipation and at the same time a thermal diffusivity that, in transients, maximizes the vapour shielding effect.The objective of the research activity here presented was to identify, through a parametric model, the optimized component configurations to be considered for this sacrificial limiter, in order to maximize its functional effectiveness. Based on the two elementary cell morphologies developed in previous studies, the parametric model allowed to investigate the combinations of relevant parameters, above all component size and geometries, armour/heat sink materials and thicknesses. Thermal optimization regarded both normal operation and two possible transient scenarios: an unmitigated plasma disruption or the Ramp Down phase. By scanning all possible combinations of parameters, those able to provide the best performances thus satisfying the user-defined functional requirements of the limiter have been identified. The thermal optimization phase was followed by CFD (Computational Fluid Dynamics) analyses in order to evaluate the potential integration of the limiter cooling circuits within the divertor Primary Heat Transfer System (PHTS) from a thermal–hydraulic point of view.

Significant enhancement of thermal conductivity and EMI shielding performance in PEI composites via constructing 3D microscopic continuous filler network

Polymer-based composites with effective heat dissipation and ideal electromagnetic interference shielding performance have gradually become an essential research focus in modern electronic industry. Herein, a method is reported by constructing 3D microscope continuous filler network into polyetherimide (PEI) matrix via incorporating function graphite nanoplatelets (GNP) with PEI microspheres, and then fillers are distributed beyond the domain area of polymer and leaded to continuous filler framework. The fabricated composites exhibit effective thermal conductivity (4.77 W m−1K−1), great EMI effectiveness (42.7 dB), ideal electrical conductivity and profound thermal property. Different scale of polymer microspheres will also change the micro-architecture from “filler-wrapped polymer” structure to “polymer-wrapped filler” structure, resulting in various thermal performance and electrical property. Finite element simulation is further employed to explore the relationship between microsphere scale and heat transfer behavior. In a word, great comprehensive performance endows PEI composites broaden prospect on the potential applications in the fields of electronic equipment.

Design and Analysis of Automobile Disc Brake using ANSYS

The application of disc brake in the growing automotive world is considered a major automotive performance factor to be considered while designing any automobile class and variants. A disc brake is one of the essential components in any automobile as it is used to turn down the speed of the automobile. During braking operation, the braking pads and discs are undergoing severe conditions of wear and high temperature. To prevent harm to the disc brake or other components, the heat generated by this disc brake must then be released into the environment. Therefore, it is crucial to provide effective heat dissipation to the environment. Increasing the surface area where heat is dissipated into the environment is one potential solution. Comparison can be done for deformation, stresses, temperature etc. form the three materials to check which material is best. Catia is a 3d modeling software widely used in the design process. ANSYS is general-purpose finite element analysis (FEA) software package. Finite Element Analysis is a numerical method of deconstructing a complex system into very small pieces (of user-designated size) called elements. The project aims to model a disc brake. Structural and Thermal analysis is done on the disc brake A proper rotor design and superior heat-dissipating material provide better performance during the braking mechanism. In this project, the optimal arrangement of holes, slots, and cut sections curved are studied by using Ansys software.

Performance evaluation with orthogonal experiment method of drop contact heat dissipation effects on electric vehicle lithium-ion battery

In order to solve the heat dissipation problem of lithium-ion power battery, a novel heat dissipation structure for lithium-ion power battery is proposed in this work, which is a drip contact heat dissipation method with transformer oil as the cooling medium. The effects of drip flow rate, drip temperature and drip position on the maximum temperature, temperature difference and energy consumption of a battery pack are investigated. The optimal scheme is obtained with orthogonal experimental design and the structure is then further optimized by the flow rate at the drip position adjustments. The results implicate that the optimal scheme is got when the drip flow rate, drip temperature of liquid are taken as 7 mL/min, 303.15 K with the drip position I at the battery cell center. The optimal structure conditions is the ratio of the liquid flow rate of the outermost ring to the inner of 0.4275:0.5725. The maximum temperature and the maximum temperature difference of the battery pack are lower than those before optimization when the battery pack are discharged in 1C, 1.5C and 2C.The time required to reach the maximum temperature of 313.15 K is increased.

Study on Optimization of Copper to Aluminum for Locomotive Finned Tube Radiator

The influence of the improvement of the finned tube radiator unit structure on the fluid flow and heat transfer effect of the locomotive was studied. A saw-toothed fin structure with aluminum instead of copper was proposed to keep the position and size of the flat copper hot water pipe unchanged. CFD simulation analysis was carried out by ICEPAK17.0, under the conditions of an ambient temperature of 24.6 °C, atmospheric pressure of 85,040 Pa and air density ρ = 0.94 kg/m3, to compare the changes of velocity field, temperature field, turbulence field and field synergy angle. The sawtooth structure of the new heat sink increases the turbulence effect of the fluid, reduces the thickness of the outer boundary layer of the water pipe, and strengthens the heat transfer effect of the radiator. Finally, the baffle height, wing window width and sawtooth angle of the sawtooth structure were selected, and the heat transfer coefficient and pressure under three conditions of low, medium and high were used as indexes to analyze the influence of each parameter on the performance of the radiator. The results show that the heat dissipation effect of the serrated aluminum sheet is higher than that of the copper sheet, the heat transfer coefficient is increased by about 1.3%, the average pressure is reduced, the turbulence performance is improved, the synergy angle is reduced by about 2.3°, and the new radiator has better performance. The fin factor has the greatest influence on the heat transfer coefficient and the least influence on the pressure. When the baffle is about 0.15 mm high, the heat transfer coefficient is the largest, and the height change has the highest effect on the pressure. The included Angle factor has the least influence on the heat transfer effect, and the influence on the pressure is higher. By changing the fin window structure, the thermal performance of the finned tube radiator can be improved.

Amine functionalization on thermal and mechanical behaviors of graphite nanofibers-loaded epoxy composites

With the growing demand for faster and more powerful computing, effective heat dissipation is essential to ensure the longevity, reliability, and high performance of electronic systems. In the field of modern electronic packaging materials, there is a great need for graphitic material-loaded polymeric composites (GPCs) with excellent thermal conductivities. However, the enhancement efficiency of GPCs is hindered by the agglomeration of fillers and the interfacial thermal resistance caused by the lack of continuous thermally conductive pathways between the filler and matrix. Understanding the interfaces between filler and matrix is of great importance in optimizing the performances of GPCs. Here, we fabricated graphite nanofibers (GNF)-loaded nanocomposites using acid-functionalized GNF (AGNF) and acid-tetraethylenepentamine-functionalized (TGNF) as a filler and epoxy resin as a matrix with different GNF loading contents to explore the interfacial properties of the nanocomposites. The optimal GNF loading for AGNF was 0.5 wt.%, while the TGNF showed 0.75 wt.%. The highest thermal conductivity (0.51 W m−1 K−1) and fracture toughness (25.8 MPa m1/2) values were found in the TGNF-loaded nanocomposites with a fraction of 0.75 wt.%, representing enhancements of ∼145% and ∼400%, respectively, compared to those of neat nanocomposites. The experimental data presented herein demonstrate that the interfacial properties play a significant role in enhancing the thermal and mechanical performances of the nanocomposites. The present approach is expected to serve as a valuable tool in the design of conductive polymeric nanocomposites for further practical applications, such as thermal interface materials and packaging of high-power electric devices.

Self-protecting concave microstructures on glass surface for daytime radiative cooling in bifacial solar cells

As a passive and compact cooling mechanism, radiative cooling is lightweight and does not consume energy. Especially for the new popular bifacial PV modules, the traditional cooling method, containing air cooling with heat sink, water cooling, phase change cooling etc. would not be suitable, and the passive radiative cooling is attracting extensive attention. In PV radiative cooling field, high emissivity materials with high visible transparency are usually used to improve the radiative heat dissipation capacity of solar cell. Most of them are polymer materials with micro-nano structural surface, which have the defects of oxidation yellowing and structural loss, and the radiative cooling film itself adds an extra thermal resistance. Hence, a variety of concave micro-nano structures based on photovoltaic glass are proposed in this work, which are protected on the inner surface of glass, making the slender structure possible, and a strong heat dissipation effect while retaining self-cleaning characteristics without covering radiative cooling films. Moreover, the spectral properties of seven kinds of structures are numerical studied, and the solar cell temperature is calculated, as well as photoelectric conversion efficiency and cooling power. The results show that the visible light transmittance of these structures is basically higher than 0.9, the emissivity of some structures between 4 and 25 μm can reach more than 0.95, the solar cell can be cooled by 2–6 °C under common environmental conditions. When Ta = 30 °C and hc = 12 W/(m2·°C), electrical efficiency is improved by 0.47% absolutely by the hemisphere, Pcooling can reach about 330 W/m2. As they are designed inside the glass, the hardness and life are greatly improved compared with previous study achievements, allowing large application potential in glass packaging PV field.

Temperature Field Analysis and Cooling Structure Optimization for Integrated Permanent Magnet In-Wheel Motor Based on Electromagnetic-Thermal Coupling

Aiming at the impact of heat generation and temperature rise on the driving performance of a permanent magnet (PM) motor, taking the PM in-wheel motor (IWM) for electric vehicles as an object, research is conducted into the temperature distribution of the electromagnetic–thermal effect and cooling structure optimization. Firstly, the electromagnetic–thermal coupling model considering electromagnetic harmonics is established using the subdomain model and Bertotti’s iron loss separation theory. Combined with the finite element (FE) simulation model established by Ansoft Maxwell software platform, the winding copper loss, stator core loss and PM eddy current loss under the action of complex magnetic flux are analyzed, and the transient temperature distribution of each component is obtained through coupling. Secondarily, the influence of the waterway structure parameters on the heat dissipation effect of the PM-IWM is analyzed by the thermal-fluid coupled relationship. On the basis, the optimization design of waterway structure parameters is carried out to improve the heat dissipation effect of the cooling system based on the proposed chaotic mapping ant colony algorithm with metropolis criterion. The comparison before and after optimization shows that the temperature of key components is significantly improved, the average convection heat transfer coefficient (CHTC) is increased by 23.57%, the peak temperature of stator is reduced from 95.47 °C to 82.73 °C, and the peak temperature of PM is decreased by 14.26%, thus the demagnetization risk in the PM is improved comprehensively. The research results can provide some theoretical and technical support for the structural optimization of water-cooled dissipation in the PM motor.