Conjugate Heat Transfer Simulation Research Articles

Numerical scheme solving the temperature of the interface between gas and heterogeneous solid with phase change

AbstractTo solve the temperature at the fluid‐solid interface in conjugate heat transfer simulations, a partitioned yet non‐iterative scheme with desirable accuracy has been developed. It takes into account the involved complex effects, for example, heterogeneous solid structure, moving interface, and phase change. The fluid and solid phases are discretized by standard Cartesian and unstructured tetrahedron meshes, respectively. At each time step the moving fluid‐solid interface is tracked with the level‐set function. The non‐iterative solution is achieved by formulating a linear system formed from the discretized interface elements, each of which, either triangular or quadrilateral, is assigned with a respective control volume constructed from adjacent grid points in both fluid and solid phases. The temperature gradient operator is treated by the node‐based Green‐Gauss formula for better robustness if the interface geometry (or mesh) is highly skewed. Numerical results demonstrate the second‐order accuracy with satisfactory robustness even on highly skewed interfaces.

The effect of channel aspect ratio on flow boiling characteristics within rectangular micro-passages

In the present paper, a fundamental analysis on the effect of the channel aspect ratio on the bubble dynamics and heat transfer characteristics for the early transient stages of the bubble growth within confined microchannels of rectangular cross-section, under saturated flow boiling conditions, is conducted, utilising high resolution, 3D, transient, conjugate heat transfer simulations. The open-source toolbox OpenFOAM is applied for the simulations, utilising a custom, user-enhanced, diabatic Volume OF Fluid (VOF) solver. Two different series of numerical simulations are performed, focused on a single nucleation event from a single nucleation site and a single nucleation event from multiple, arbitrarily located, nucleation sites, respectively. In each series, three different values of channel aspect ratio are considered, corresponding to a narrow, a square, and a wide microchannel. For the first series, the simulations are performed for a low, a medium, and a high value of applied heat flux and mass flux. For the second series, only the lower values of applied heat flux and mass flux are used for each channel aspect ratio, since this constitutes the worst-case scenario from the overall heat transfer performance point of view, amongst the cases examined in the first series of simulations. The micro-passage aspect ratio has a significant effect in the generated bubble dynamics during the onset of the nucleate boiling regime, as the bubbles grow within the confined liquid crossflow. This alteration of the generated interfacial dynamics, in effect, regulates the size and position of the contact areas of the generated bubbles with the microchannel walls, with a direct effect in the individual contribution and therefore, the balance between the contact line and the liquid film evaporation mechanisms. Moreover, the work presents the quantification of the effect of the solid domain thermal inertia on the whole process and in particular on the local Nusselt numbers. It is evident that considering conjugate heat transfer in numerical simulations of flow boiling is compulsory in order to predict the physical processes in a correct form.

Performance Analysis of Single-Phase Space Thermal Radiators and Optimization Through Taguchi-Neuro-Genetic Approach

Abstract In the thermal management of spacecraft, space thermal radiators play a vital role as heat sinks. A serial radiator with proven advantages in ground applications is proposed and analyzed for space applications. From the performance analysis, specific heat rejection (SHR) of serial radiator is found to be higher than parallel radiator by 80% for maximum diameter of the tube, 47% for maximum thickness of the fin, and 75% for maximum pitch of the tubes under consideration. Also, serial radiator requires four times higher pumping power than parallel radiator with geometric parameters and a maximum mass flowrate under consideration. In serial radiators, the cross conduction between the fins has a significant effect on its thermal performance. Thus, conjugate heat transfer simulations and optimization operations are to be performed iteratively to optimize the serial radiator, which is computationally costly. To reduce the computational time, artificial neural network (ANN) is trained using conjugate heat transfer simulations data and combined with the genetic algorithm (GA) to perform optimization. Taguchi’s orthogonal arrays provided the partial fraction of conjugate heat transfer simulations set to train the ANN. Taguchi-Neuro-Genetic approach, a process that combines the features of three powerful techniques in different optimization phases, is used to optimize both parallel and serial radiators. The optimization aims to obtain a configuration that provides the lowest mass and lowest pumping power requirement for given heat rejection. Optimization results show that the conventional parallel radiator is about 20% heavier and requires about 35% more pumping power than the proposed serial radiator.

Analysis of the Cooling Concept of the Braking System of a Formula Student Racing Car Using CFD Simulation and 1D Simulation

In order to guarantee the performant operation of the braking system of a racing car under high load an optimized thermal design of the braking system is an important factor. Especially in motorsports, a lot of braking energy is converted into heat due to short and intense braking events. Therefore, a suitable cooling concept is a crucial point to ensure a reliable thermal management of the braking system to dissipate the generated heat. In this work, the braking system of the formula student racing car of the UAS Esslingen is analysed using the racing car of the season 2019. A transient 1D simulation model of the heat balance of the braking system is created. For the determination of the heat transfer coefficients a steady 3D Conjugate Heat Transfer (CHT) simulation model is set up. The logging data of a real race are used for the validation of the presented model (s). The heat balance of the braking system, its entire heat flows as well as the time-dependent temperature evaluation of the brake disc are analysed and compared. The results of this analysis are used to create a cooling concept for the racing car’s braking system, to ensure an optimized braking performance over the entire race. Several different (geometrical) variants of the thermal design of the braking system are investigated using the above mentioned numerical models and the results are presented. Furthermore, the implementation of a cooling duct for the braking system is studied.

Numerical analysis on the thermal performance of microchannel heat sinks with Al2O3 nanofluid and various fins

• A single-phase three-dimensional flow model compares different finned microchannels. • The fin shape has significant effects on microchannel heat transfer characteristics. • A zigzag fin gives the highest rate of heat removal to hydraulic power loss ratio. • The zigzag fin gives a 9 K lower contact temperature and 60% higher Nusselt number. • Higher thermal performance is achieved with the Al 2 O 3 nanofluid compared to water. The hydraulic and thermal performance of microchannel heat sink configurations for high performance electronic cooling applications is investigated by numerical modelling. Conjugate heat transfer simulations are obtained through the silicon walls and the fluid domain of a square base prism heat sink traversed by 50 parallel rectangular cooling ducts, under a 150 W/cm 2 constant heat flux input through the base. Al 2 O 3 nanofluid coolant with a nanoparticle volume fraction ranging from 0 to 3% is supplied at 298 K, over the Reynolds number range 100 to 350, modelled as a single-phase homogeneous medium. Rectangular, twisted, and zig-zag fins are inserted into the plain rectangular duct to enhance the heat transfer rate. The zig-zag fin and 3% Al 2 O 3 nanofluid provide the best thermal performance, with a 6.44 K lower average heated wall contact temperature, 60% higher Nusselt number, and 15% higher second law efficiency than without fins and plain water cooling. Twist in the microchannel fin unexpectedly reduced the microchannel pressure drop by 2% to 15% compared to a straight fin, possibly due to the more evenly distributed axial mass flux across the microchannel.

Aerodynamic port-aligned fins to enhance thermal-hydraulic performance of jet impingement arrays

Jet impingement arrays with interspersed fluid extraction ports can suffer degraded heat transfer near outlets due to flow separation. This study explores the potential to integrate aerodynamic port-aligned fins on the impingement surface to maintain wall-jet attachment and increase heat transfer area. Such fins may also enhance local transport under inlet nozzles. Laminar-flow conjugate heat transfer simulations are performed for a range of Reynolds numbers and geometries to characterize this concept for slot jet impingement arrays. The simulation methodology is validated with conventional slot jet data from the literature and demonstrated to achieve mesh convergence. Overall flow characteristics are evaluated for a representative geometry, and results show a significant increase in relative average Nusselt number (Nu∗‾)and a reduction in peak temperature of the cooled surface. Conjugate heat transfer effects are evaluated, and are found to be significant for lower conductivity fin materials. Parametric studies are performed to generate performance maps for relative average Nusselt number and pressure drop as functions of Reynolds number, fin height, base width, and tip radius. Pareto curves are generated for the geometries that optimally trade heat transfer enhancement and pressure drop penalty to guide design. Teardrop shaped fins are found to be optimal for low Re, whereas continuously narrowing fins are preferable for higher Re. This jet impingement enhancement is shown to deliver up to 25% enhancement in Nu∗‾ at baseline pressure drop.

Evaluation of porous rib and flow pulsation on microchannel thermal performance using a novel thermal lattice Boltzmann method

In this study, a new thermal lattice Boltzmann model (TLBM) is developed to simulate conjugate heat transfer in a microchannel heat sink (MCHS) with porous ribs and pulsatile flow inlet. The examined parameters include the rib to channel height ratio (Hr*), Strouhal number (St), and Reynolds number (Re), which are varied from 0.25 to 0.75, 0 to 3.2, and 100 to 300, respectively. The proposed TLBM is based on the double distribution function framework and capable of addressing heat transfer in combined fluid and porous media conditions. The simulation data show that the flow pulsation inside MCHS with porous ribs not only improves the bulk mean temperatures but also eliminates the rib recirculation zones at some phases, which promotes both the local and overall heat transfer. For fixed Re, the overall Nusselt number (Nu‾/Nu0) and Fanning friction coefficient (f‾/f0) increase and then decrease with increasing St. The maximum values appear at St = 2. For fixed Re and St, the thermal performance factor (TPF) displays a single peak trend with Hr* and the optimal TPF of 2.2 occurs at Hr*=0.5. In addition, compared with the previous ribbed, baffled, and porous MCHSs, the proposed porous rib design under pulsating conditions reports the highest Nu‾/Nu0 of 13.4 in the range of f‾/f0≤200. Finally, the correlations of Nu‾/Nu0 and f‾/f0 with Re, St, and Hr* for the present MCHS are established for the first time, with average differences below 6.7% and 12.4%, respectively.

Impact of wall heat transfer in Large Eddy Simulation of flame dynamics in a swirled combustion chamber

Large Eddy Simulation (LES) is a fundamental research tool to study gas turbines and aero-engine combustors. In LES, although rarely addressed systematically, it is known that thermal boundary conditions control the heat transfer between the flow and the combustor walls. This work presents a study on the impact of thermal wall boundary conditions for the PRECCINSTA test bench, operated by the German Space Agency (DLR). Two approaches are tested: Heat Resistances Tuning (HRT), where a local resistance is tuned using experimental temperature data, and full Conjugate Heat Transfer (CHT), where the chamber wall-temperature is solved and coupled to the flow computation. Results reveal that the HRT method captures the mean flame correctly but the predicted flame becomes unstable and responds to a thermoacoustic oscillation which is not observed experimentally. On the contrary, using CHT, the flame is correctly predicted and stable as in the experiments. Finally, to understand the differences between the HRT and the CHT simulations, Dynamic Mode Decomposition (DMD) analysis is performed showing that the correct response of the flame branches to the pressure oscillations is recovered only in the CHT simulations for which thermoacoustically stable operations are retrieved.

Analysis and simulation of thermal performance of a PTC with secondary reflector

In this paper, a numerical simulation of fluid flow and conjugate heat transfer in a solar thermal parabolic trough collector (PTC) system is presented. The simulation is being carried out on a prototype designed in the Mechanical Laboratory in order to analyze the performance of this system. The main objective is to compare the system performance with and without a secondary reflector (SR). PVSYST software is used to provide numerical temporal values of the solar heat flux in Laghouat city (ALGERIA). Solar flux density values for four days in different seasons have been taken. SolTrace code is used to determine the heat flux distribution on the absorber tube. The conjugate heat transfer and fluid flow equations in the tube absorber are solved by using ANSYS-CFX CFD software. A comparison between two cases (traditional PTC and PTC with parabolic secondary reflector) with the same working fluid (Therminol VP-1) is carried out. The obtained results show that the system performance are practically the same for the four seasons. Moreover, the performance of the system with a second collector is better than that without a second reflector with a ratio of about 1.65.

Conjugate Heat Transfer Simulation and Cooling Optimization of the Flow inside a Screw Compressor

Computational Fluid Dynamics (CFD) as a predictive tool is playing an increasing role in the design and optimization process at Compressors and Vacuum Pumps Systems (CVS) Engineering GmbH. Design optimization using Design of Experiment (DoE) and continuous improvement of our products has led to an increase in the use of CFD and other predictive tools. This paper investigates the use of CFD combined with Conjugate Heat Transfer (CHT) to optimize the flow and the cooling inside a rotary screw compressor.

Bi-Fo time scaling method in the numerical simulation of transient conjugate heat transfer

Reliable transient thermal analysis plays a very important role in the engine safety analysis. Transient conjugate heat transfer simulation is an important way of temperature analysis. But there exists a great disparity in the time scales between solid conduction and fluid convection. The calculation cost of transient conjugate heat transfer analysis is very huge because of the tiny time step of computational fluid dynamics. The Bi-Fo time scaling method is proposed to improve the computational efficiency of transient conjugate heat transfer. On the one hand, this method carries out a similar transformation on solid heat conduction, scaling the calculation time with the product of density and specific heat capacity to maintain the consistency of Fourier number. On the other hand, it takes very short time for the fluid domain to recover stability after a boundary disturbance. Based on the above characteristic, the flow time is directly compressed to the same as that of the solid domain. It is verified by Mark Ⅱ vane that increasing the solid thermal diffusivity can reduce the time scale of heat conduction. In the situation of rapidly stable flow field, scaling flow time does not affect the solid thermal boundary under corresponding dimensionless time. Within the application scope, the Bi-Fo time scaling method can greatly reduce the time cost of transient conjugate heat transfer simulation while maintaining the accuracy of transient temperature analysis.

A comprehensive study on parametric optimization of the pin-fin heat sink to improve its thermal and hydraulic characteristics

In an effort to reduce the highest temperature of electronic pieces, using high performance cooling systems is required, and for this reason, optimization is one of the most essential and attractive issues that has an undeniable role in industry and technology. In this study, a finite volume method is employed to numerically simulate conjugate heat transfer in pin-fin heat sinks, which are of the most common cooling systems, and all the geometric parameters affecting their performance are optimized based on thermal and hydraulic performances (FOM). These geometric parameters are: the number of fins, the fin height, the fin diameter, and the transverse pitch. It will be shown that the total performance of the pin-fin heat sink improves step by step by optimizing these parameters. Also, it will be suggested that the shape of pin-fins changes to a tapered one. It is proved that changing the fin shape has a significant influence on the convective heat transfer coefficient and pressure drop and enhances the total performance of the system. Furthermore, it is observed that the total performance of the pin-fin heat sink increases more than 17% during the stages of the optimization.

Conjugate heat transfer simulation of sulfuric acid condensation in a large two-stroke marine engine - the effect of thermal initial condition

In the present study, conjugate heat transfer (CHT) calculations are applied in a computational fluid dynamics (CFD) simulation to simultaneously solve the in-cylinder gas phase dynamics and the temperature field within the liner of the engine. The effects of different initial temperatures with linear profiles across the liner are investigated on the wall heat transfer as well as on the sulfuric acid formation and condensation. The temporal and spatial behavior of sulfuric acid condensation on the liner suggests the importance of CHT calculations under large two-stroke marine engine relevant conditions. Comparing the mean value of the heat transfer through the inner and outer sides of the liner, an initial temperature difference of 15 K with a linear profile is an appropriate initial condition to initiate the temperature within the liner. Moreover, the effect of the amount of water vapor in the air on the sulfuric acid formation and condensation is studied. The current results show that the sulfuric acid vapor formation is more sensitive to the variation of the water vapor amount than the sulfuric acid condensation.

Effect of an on/off HVAC control on indoor temperature distribution and cycle variability in a single-floor residential building

This paper investigates an influence of an intermittent on/off operation of the air-conditioning (AC) equipment on the indoor temperature distribution, air flow and a cycle variability within a single-floor medium-size residential house. The analysis is performed using a recently developed and well validated computational tool based on a Computational Fluid Dynamics (CFD) method, coupled with conjugate heat transfer simulations within a three-dimensional model of a solid building envelope, and an HVAC on/off control model. The importance of including unsteady minute-level dynamic effects associated with the cycling of AC equipment into the energy and thermal analysis of residential and commercial buildings was recently recognized. Despite that, there were no studies that examined the effect of on/off cycling on the physics of the air mixing during both cooling and heating stages of the AC cycle, and how these unsteady interactions effect both the energy consumption and its variability, and the indoor thermal environment linked to a thermal comfort of the building occupants. The current paper focuses on analyzing the duration and variability of the cooling and heating cycles and their effect on the temperature distribution inside a residential house. It is found that both heat transfer from the walls, and turbulent intermittency of the indoor air affect the duration of the cooling and heating cycles. It is demonstrated that a central air system controlled by a single thermostat placed in the hallway results in a consistent overcooling of the interior spaces. These findings are important for the considerations of the electric grid management, and for the improvement of HVAC systems design and control.

Simulation of turbulent flow subjected to conjugate heat transfer via a dual immersed boundary method

In the context of turbulent flows, this study presents a new methodology for the high-fidelity simulation of conjugate heat transfer between solid and fluid. The numerical strategy is mainly based on the immersed boundary method to ensure the expected thermal boundary condition at the fluid/solid interface. The approach is dual since the solid domain is the immersed region for the fluid and, conversely, the fluid for the solid. The resulting method is an extension of an already existing immersed boundary method based on the reconstruction of the solution inside the immersed region. The duality of the technique requires to define one temperature field for the fluid and another one for the solid. The interaction between the two temperature fields is ensured, at the fluid/solid interface, through an efficient weak coupling preserving numerical stability and accuracy. Thanks to the reconstruction in its own immersed zone, each temperature field solution is perceived as smooth by the numerical differentiation method, for any fluid-to-solid ratio of thermal conductivities and diffusivities, while representing a desirable sharp interface. This feature is crucial for the high-order finite difference schemes used in this work. The method is validated for the plane channel and pipe flow configurations and a demanding pure conduction case with variable conductivity in a composite wall. Its ability to preserve second-order accuracy in space is checked in the laminar and pure conduction cases by comparison with analytical solutions. In the turbulent case, the assessment is based on comparisons of basic turbulent statistics with reference data obtained by direct numerical simulation. The step-by-step analysis of thermal statistics shows that the present immersed boundary method can ensure accurately imposed temperature, imposed heat flux, and conjugate heat transfer conditions at the fluid/solid interface.

Prediction of Liner Metal Temperature of an Aeroengine Combustor with Multi-Physics Scale-Resolving CFD.

Computational Fluid Dynamics is a fundamental tool to simulate the flow field and the multi-physics nature of the phenomena involved in gas turbine combustors, supporting their design since the very preliminary phases. Standard steady state RANS turbulence models provide a reasonable prediction, despite some well-known limitations in reproducing the turbulent mixing in highly unsteady flows. Their affordable cost is ideal in the preliminary design steps, whereas, in the detailed phase of the design process, turbulence scale-resolving methods (such as LES or similar approaches) can be preferred to significantly improve the accuracy. Despite that, in dealing with multi-physics and multi-scale problems, as for Conjugate Heat Transfer (CHT) in presence of radiation, transient approaches are not always affordable and appropriate numerical treatments are necessary to properly account for the huge range of characteristics scales in space and time that occur when turbulence is resolved and heat conduction is simulated contextually. The present work describes an innovative methodology to perform CHT simulations accounting for multi-physics and multi-scale problems. Such methodology, named U-THERM3D, is applied for the metal temperature prediction of an annular aeroengine lean burn combustor. The theoretical formulations of the tool are described, together with its numerical implementation in the commercial CFD code ANSYS Fluent. The proposed approach is based on a time de-synchronization of the involved time dependent physics permitting to significantly speed up the calculation with respect to fully coupled strategy, preserving at the same time the effect of unsteady heat transfer on the final time averaged predicted metal temperature. The results of some preliminary assessment tests of its consistency and accuracy are reported before showing its exploitation on the real combustor. The results are compared against steady-state calculations and experimental data obtained by full annular tests at real scale conditions. The work confirms the importance of high-fidelity CFD approaches for the aerothermal prediction of liner metal temperature.

Experimental Study and Conjugate Heat Transfer Simulation of Pulsating Flow in Straight and 90° Curved Square Pipes

The turbulent pulsating flow and heat transfer in straight and 90° curved square pipes are investigated in this study. Both experimental temperature field measurements at the cross-sections of the pipes and conjugate heat transfer (CHT) simulation were performed. The steady turbulent flow was investigated and compared to the pulsating flow under the same time-averaged Reynolds number. The time-averaged Reynolds number of the pulsating flow, as well as the steady flow, was approximately 60,000. The Womersley number of the pulsating flow was 43.1, corresponding to a 30 Hz pulsating frequency. Meanwhile, the Dean number in the curved pipe was approximately 31,000. The results showed that the local heat flux of the pulsating flow was greater than that of the steady flow when the location was closer to the upstream pulsation generator. However, the total heat flux of the pulsating flow was less than that of the steady flow. Moreover, the instantaneous velocity and temperature fields of the simulation were used to demonstrate the heat transfer mechanism of the pulsating flow. The behaviors, such as the obvious separation between the air and pipe wall, the low-temperature core impingement, and the reverse flow, suppress the heat transfer.

Thermal Analysis and Creep Lifetime Prediction Based on the Effectiveness of Thermal Barrier Coating on a Gas Turbine Combustor Liner Using Coupled CFD and FEM Simulation

Thermal barrier coating (TBC) plays a vital role in the gas turbine combustor liner (CL) to mitigate the internal heat transfer from combustion gas to the CL and enhance the parent material lifetime of the CL. This present study examined the thermal analysis and creep lifetime prediction based on three different TBC thicknesses, 400, 800, and 1200 μm, coated on the inner CL using the coupled computational fluid dynamics/finite element method. The simulation method was divided into three models to minimize the amount of computational work involved. The Eddy Dissipation Model was used in the first model to simulate premixed methane-air combustion, and the wall temperature of the inner CL was obtained. The conjugate heat transfer simulation on the external cooling flows from the rib turbulator, impingement jet, and cross flow, and the wall temperature of the outer CL was obtained in the second model. The thermal analysis was carried out in the third model using three different TBC thicknesses and incorporating the wall data from the first and second model. The effect of increasing TBC thickness shows that the TBC surface temperature was increased. Thereby, the inner CL metal temperature was decreased due to the TBC thickness as well as the material properties of Yttria Stabilized Zirconia, which has low thermal conductivity and a high thermal expansion coefficient. With the increase in TBC thickness, the average temperature difference between the TBC surface and the inner metal surface increased. In contrast, the average temperature difference between the inner and outer metal surfaces remained nearly constant. The von Mises equivalent stress, based on the material property and thermal expansion coefficient, was determined and used to find the creep lifetime of the CL using the Larson–Miller rupture curve for all TBC thickness cases in order to analyze the thermo-structure. Except in the C-channel, the increasing TBC thickness was found to effectively increase the CL lifespan. Furthermore, the case without TBC was compared with the damaged CL with cracks due to thermal stress, which was prevented by increasing TBC thickness shown in this present study.

Application of Nonlinear Krylov Solvers for Conjugate Heat Transfer Simulations of Electrical Battery Packs

Abstract Krylov-based methods are an attractive alternative to traditional fixed-point iterative schemes, being much more robust and accurate when solving elliptic equations (e.g., the energy equation in the solid domain). This study assesses the performance of a Krylov-based accelerator, when used for conjugate heat transfer (CHT) simulations of an electrical battery pack. The nonlinear nature of CHT simulations (due to spatial and temporal changes in boundary conditions) necessitates the use of the non-inear form of the Krylov-based accelerator (termed NKA), which utilizes the generalized minimized residual (GMRES) method, and works by accelerating an existing fixed-point iteration scheme. NKA is used while performing steady-state CHT simulations of an air-cooled lithium-ion battery pack, specifically to help accelerate the solution of the solid domain energy equation. The effect of using either isotropic or anisotropic thermal conductivity within the cylindrical lithium-ion battery cells is also evaluated. Results obtained using the NKA accelerator are compared, in terms of accuracy and speed, with those obtained from a traditional nonlinear fixed-point iterative scheme based on successive over-relaxation (SOR). The NKA accelerator is found to perform quite well for the problem at hand, providing results with the specified accuracy, while also being between 5 and 20 times faster than SOR (while solving the solid energy equation). The robust nature of NKA also leads to better global heat balance within the battery pack at all times during the simulation. These observations hold for both the isotropic and anisotropic thermal conductivity conditions. Overall, computational cost reductions of 30–40% are observed when using NKA for the battery pack simulations. Although the performance of NKA is demonstrated for a battery cooling application, NKA performs quite well in other applications also.

Design analysis of the “Schwartz D” based heat exchanger: A numerical study

Triply Periodic Minimal Surfaces (TPMS) have promising thermophysical properties, which makes them a suitable candidate in the production of low-temperature waste heat recovery systems. A TPMS thermal performance is connected to the complex flow patterns inside the pores and their interactions with the walls. Unfortunately, the experimental study’s design analysis and optimization of TPMS heat exchangers are complicated due to the flow pattern complexity and visual limitations inside the TPMS. In this study, three-dimensional steady-state, conjugate heat transfer (CHT) simulations for laminar incompressible flow were carried out to quantify the performance of a TPMS based heat exchanger. TPMS Lattices based on Schwartz D architecture was modeled to elucidate the design parameters and establishing relationships between gas velocity, heat transfer, and thermal performance of TPMS at different wall thicknesses. In this study, four types of lattices from the same architectures with varying wall thickness were examined for a range of the gas velocity, with one design found to be the optimized lattice providing the highest thermal performance. The results and methodology presented here can facilitate improvements in TPMS-heat exchangers’ fabrication for recycling the waste heat in low pitch thermal systems.