Surface Temperature Difference Research Articles

Thermo-fluidic analysis of microchannel heat sink with inline/staggered square/elliptical fins

The present study reports the thermo-fluidic behavior of a microchannel heat sink employed over a heat source dissipating a heat flux of 50 W/cm2. The microchannel heat sink is embedded with elliptical and square fins varied from 11 × 3 (11 fins per row with a total of 3 rows) to 79 × 3 fins and 100 μm to 300 μm height to obtain the optimum configuration for maximum heat transfer and minimum frictional loss. Fluid flow is considered in the laminar range of Re varying from 100 to 400. The problem is solved numerically using a Finite Volume Method based multigrid solver of ANSYS Fluent. The aim of the present study is to investigate the shape effect of square fin (α = 0), square fin (α = 45) and elliptical fins on the heat transfer from the heater surface and frictional loss. This is achieved by keeping the correctional area and the surface the same for all types of fins. It is found that the heater surface temperature monotonously decreases with the number of fins for a fin height more than 200 μm. When different fin shapes are compared, no remarkable difference in the heater surface temperature is observed; however, elliptical fins are marginally more effective for a greater number of fins than the square fin with α = 0 followed by α = 45. Increasing the fin height results in augmenting the heat transfer for all cases. When different arrangements are compared, staggered fins result in slightly better heat transfer than the inline fins except 11 × 3 and 79 × 3 fins. As far as friction factor is concerned, elliptical fins with staggered arrangement provide the least frictional resistance.

Investigation of the Liquid Cooling and Heating of a Lithium-Ion Battery Package for an Electric Vehicle

The temperature of an electric vehicle battery system influences its performance and usage life. In order to prolong the lifecycle of power batteries and improve the safety of electric vehicles, this paper designs a liquid cooling and heating device for the battery package. On the device designed, we carry out liquid cooling experiments and preheating experiments. Then, a three-dimensional numerical model for the battery package is built, and its effectiveness is validated by comparing the simulation results with the experimental outcomes in terms of battery surface temperature and temperature difference. Furthermore, we investigate the influences of the liquid flow rate and the inlet temperature on the maximum temperature and temperature difference of batteries by the cooling models and preheating models. Results show that: at the cooling stage, it is able to keep each battery working at an optimal temperature under different discharge conditions by changing the flow and the inlet temperature of liquid; at the heating stage, large flow rates and high inlet temperatures are able to speed up the preheating process, thereby saving time of the drivers.

A multi-level early warning strategy for the LiFePO4 battery thermal runaway induced by overcharge

The thermal runaway (TR) of lithium-ion batteries (LIBs) is difficult to control when it reaches the late stage, which results in disastrous accidents, while the current means of early warning are biased late or inaccurate. Therefore, an early monitoring and warning strategy is necessary for LIB to mitigate TR. In this study, overcharge tests on LiFeO4 batteries were conducted at various current rates (C-rates). The evolutions of voltage, gas, and temperature during overcharge were analyzed, and the TR process could be divided into four stages: Stage I (initial stage), Stage II (gas detected stage), Stage III (reaction accelerating stage), Stage IV (post-TR stage). The maximum surface temperature difference (ΔTmax) exceeded 5 °C in Stage II. Incremental capacity analysis (ICA) and differential voltage analysis (DVA) were used to reveal the internal mechanism when different gases were detected in Stage II, and the safety performance of the LIB was affected severely. To avoid TR of LIB, it was necessary to start early warning in Stage II. A Three-Level warning strategy was proposed based on the voltage turning point (VTP), temperature, and the appearance of various gases in Stage II. A reliable warning before the TR was achieved by setting the threshold effectively, and the TR event was mitigated successfully. These findings provide a critical basis to enhance the monitoring and warning capability of the battery management system as well as battery safety.

Interdecadal Variation of Spring Extreme High-Temperature Events in the Western Tianshan Mountains and Its Relationship with the Tropical SST

This study performed an observational analysis to examine the interdecadal variation in the frequency of extreme high-temperature events (EHEs) during spring over the western Tianshan mountain, China, which were characterized by relatively fewer (more) EHEs during 1983–1996 (2000–2015). A composite analysis indicated that the interdecadal increase in EHEs is closely related to a deep dynamic anomalous Iranian high. Under the control of this high system, the water vapor content decreased over the western Tianshan mountains, and atmospheric circulation was dominated by a descending motion. Both were attributed to the decreased cloud cover, inducing a cloud-forced net solar radiation increase. The short-wave radiation flux and sensible heat flux reaching the surface increased, and the net surface heat flux increased cumulatively, which was conducive to the surface temperature increase and EHE occurrence. The anomalous Iranian high responsible for ECEs occurrence was related to the air-sea interaction over the Atlantic and Indo-Pacific. The latitudinal sea surface temperature (SST) difference between the tropical western Pacific and the western Indian Ocean directly strengthens the Walker circulation and thus enhances the Iranian high. In addition, the anomalous Iranian high was affected by the atmospheric wave trains at middle latitude, which was triggered by the warm anomaly of the Atlantic SST.

Experimental Study on the Thermal Performance of Flat Loop Heat Pipe Applied in Data Center Cooling

The cooling system is the auxiliary equipment that consumes the most energy in a data center, accounting for about 30 to 50% of the total energy consumption. In order to effectively reduce the energy consumption of a data center, it is very important to improve the heat exchange efficiency at the chip level. Compared with air cooling, single-phase cold plate liquid cooling, and immersion liquid cooling, the flat loop heat pipe (FLHP) is considered to be a better chip-level cooling solution for data centers. It has extremely high heat transfer efficiency and heat flux variability, and it can avoid the operation risk caused by liquid entering the server. In this paper, a FLHP with an evaporator designed with a “Tesla valve” flow channel configuration is developed. Experiments on the FLHP are carried out, focusing on the installation angles and cooling condition factors. The results show that an inclination angle of 20° is the critical point of the influence of gravity on the performance of the FLHP; to ensure good operation of the FLHP, the installation angle should be greater than 20°. The equivalent heat transfer coefficients of the FLHP condenser under different cooling conditions are calculated. It is found that water cooling can provide higher cooling heat transfer coefficients with lower energy consumption and operating noise. Additionally, the heat transfer limit, operating temperature uniformity, and start-up stability of the FLHP are significantly improved under water cooling conditions. The maximum heat load of the FLHP is up to 230 W, and the temperature difference of the evaporator surface can be controlled within 0.5 °C, under 20 °C water cooling. Finally, using the FLHP for thermal management of the chip, its heat transfer efficiency is 166 and 41% higher than that of air cooling and water cooling, respectively.

Asymmetric Impacts of El Niño Development and Decay Stages on the Hadley Circulation

AbstractThe impact of El Niño on the Hadley Circulation (HC) has been a topic of previous studies, but the results have been inconclusive. We study how El Niño affects the HC during different stages of its cycle. In development years, the HC anomaly shows an equatorial quasi‐symmetric pattern, while in decay years, it shows an asymmetric pattern. This resolves previous discrepancies among studies about El Niño's impacts on the HC. The differences in tropical sea surface temperature (SST) during different stages of El Niño cause differences in SST meridional gradients, which determine the location of convergence. This explains why the HC anomalies have different spatial structures during El Niño development and decay years. Our results show that the meridional distribution of SST during different El Niño stages has significantly distinct impacts on meridional circulation and clarify the differences in El Niño's effects on climate.

Thermal analysis of concrete bricks-embedded phase change material: A case study under hot weather conditions

This research experimentally examines the thermal behaviour of concrete brick-based PCM layer/capsules during severe hot summer days in southern Iraq. Three bricks were fabricated in which one brick was integrated with a PCM layer (BL) and another integrated with PCM capsules (BC), while the third was left bare without PCM (BR) for comparison. The thermal performance of bricks was assessed considering the inner and outer surface temperature difference, decrement factor, time lag and average surface temperature fluctuation reduction. Besides, the mechanical strength decline of each brick was investigated to show their applicability in real constructions. Experimental results designated that BL and BC performed better than BR, in which the temperature across the brick was shaved by up to 5 °C with a 30–60 min time lag. Generally, BL exhibited slightly better thermal performance than BC; nonetheless, it showed a sharp decline in compression strength. Conclusively, the brick-based PCM layer was thermally better than that-based PCM capsules, but the latter has superior mechanical properties.

Divergent urbanization-induced impacts on global surface urban heat island trends since 1980s

Urbanization experiences different speeds and forms under diverse development stages across the globe. However, urbanization-induced impacts on long-term surface urban heat island intensity (Is) trends across global cities and the regulators of such impacts remain understudied Here we estimate interannual trends in daytime Is (i.e., urban-rural differences in surface temperatures) across 511 major cities for 1985–2020 using annual averages calculated using reconstructed land surface temperature data derived from >250,000 Landsat thermal images. Our study reveals that the global mean Is growth rate is 0.156 °C/decade. We further examine Is change associated with per 1% impervious land growth (denoted as β) in each city throughout the research period and during different periods. The global mean β is 0.018 ± 0.025 °C/% (mean ± 1 standard deviation) for the whole period, with greater values in humid than in arid climates; and the β may change during different periods, e.g., it has more than tripled when urban impervious land exceeds 30%, indicating the spatiotemporally divergent impacts of urbanization on Is trends across global cities. The spatial variations in β across global cities are well correlated with rural vegetation abundance and precipitation but not with urban population. Among these three factors, rural vegetation abundance possesses the greatest standardized regression coefficient of partial least-squares model, signifying the critical role of biome background in regulating β. The finding implies that future urbanization over densely vegetated regions should be more carefully and strategically planned due to the greater urbanization-induced surface warming effect.

Polycentric structure and urban thermal environment: A large-scale study from multi-perspectives

Polycentric development is a widespread tendency, and urban thermal environment is unavoidably changed in this context. Using data from 265 Chinese cities, we explore urban thermal environment under polycentric development from three perspectives. First, we analyze the correlation between three metrics describing polycentricity and surface urban heat islands (SUHI) at the urban scale, taking into account diurnal and seasonal differences. Second, we examine the surface temperature difference between the main center and subcenter(s) as well as its possible influencing factors. Third, we use structural equation modeling to quantitatively confirm the mechanism behind the relationship between polycentric structure and SUHI. The results show that: (1) There is a significant positive correlation between polycentricity and daytime SHUI, regardless of the season. However, the relationship is insignificant during summer nighttime, and it even becomes negative during winter nighttime. (2) The majority of the main centers experience more severe thermal challenges. (3) Climate, urban size, vegetation, and industry are the mediators of the relationship between SUHI and polycentric structure during summer daytime. Our findings provide valuable insights for understanding thermal environment under polycentric development and can be used as a reference for proposing thermal mitigation strategies for cities that are or are becoming polycentric.

Influence of solar radiation on the surface loss of the painted statues in Grotto No. 3 of Maijishan Grottoes, China

The embedded hygrothermal environment of cultural heritages (solar radiation, temperature, humidity, etc.) plays a significant role in their conservation and survival, especially in the case of outdoor ones. The surface loss of painted statues is often related to fluctuations in the surface temperature caused by the ever-changing solar radiation; however, the quantitative relationship between them remains unclear. To clarify, in this paper, hygrothermal monitoring and numerical simulation were conducted on painted statues with an age of over 1400 years in the World Heritage Maijishan Grottoes. The results showed that the ruined eaves have led to significant differences in solar radiation intensity and surface temperature between the upper and lower statues, with maximum values of 598.7 W/m2 and 13.6 °C, respectively, corresponding to surface loss rates of nearly 15% and 50%. Under the influence of direct insolation, the thermal stress on the statue surface increased with decreasing height, resulting in a difference of 10.8 kPa between the highest and lowest points. Taking the tensile strength of clay (10 kPa) as a threshold of thermal stress, the yearly number of events exceeding this threshold at the upper and lower rows were 2819 and 3173, respectively. Overall, direct insolation has a significant effect on the temperature changes on painted statue surfaces, thus leading to greater thermal stress and greater degrees of surface loss. For heritages in open or semi-open environments, it is necessary and effective to evaluate their preservation conditions based on the threshold and then propose suitable conservation methods for preventive protection.

Temperature field model of limited slip clutch based on dynamic heat flux partition characteristics

The interaxle torque distribution of off-road vehicle is interfered with temperature field variation of limited slip clutch during long-time sliding, which is controlled by actual heat flux input. The equivalent heat dissipation model is created based on the suggested calculation method of convective heat transfer equivalent coefficient in various lubrication phases. Further, thermal equilibrium equations of friction pair nodes are solved to produce the temperature field calculation model of dynamic heat flux partition. A clutch sliding bench is set up to verify and analyze the effect of heat flux partition on temperature field by organizing different operating conditions. The results demonstrate that the temperature difference of contact surface calculated by the constant heat flux partition model increases significantly along with sliding time and heat flux. In addition, the deviations of temperature rising rate at stage A and average temperature at stage B of separator plate higher than the experimental result also increases. On the contrary, the decrease value of actual input heat flux of separator plate from initial to steady state gradually increases with the increase of relative speed difference in dynamic heat flux partition model. The calculation deviations of temperature rising rate and average temperature are less than 0.1°C/s and 3°C, respectively. This model offers a novel approach for calculating clutch temperature field.

Where should the thermal image sensor of a smart A/C look?-Occupant thermal sensation model based on thermal imaging data

Applying thermal imaging sensor to air conditioner for monitoring human thermal sensation and achieving dynamic settings may satisfy occupants' thermal needs while saving energy. The existing studies are mostly based on single-view imaging to build the model and ignore the possible differences in body surface temperature on thermal sensation response by gender, etc., which may have many limitations. Subject experiments were conducted in an artificial climate chamber to obtain subjective questionnaires and thermal images of the exposed frontal face, lateral face, top of the head, forearm, and hand dorsum of 27 subjects in this study. By applying machine learning classification algorithms and global optimal regression algorithms, the temperature collection zones that can accurately reflect the thermal sensation of both genders in each view were analyzed, and a two-stage thermal sensation assessment model applicable to multiple views was developed. Of the various imaging views, the frontal view of the face is the best, followed by the lateral view of the face, the top view of the head, and the forearm/hand dorsum view. For male and female, the mean absolute errors of the thermal sensation assessment model established were 0.41–0.49 and 0.50–0.53 thermal sensation units. In addition, gender differences were found in the response of head surface temperatures to thermal sensation. The results obtained can provide a reference for the application of thermal image sensor to smart air conditioners.

Comparative analysis of the thermal insulation performance of a façade enclosure integrated by vegetation under simultaneous windy and rainy climatic conditions

The literature offers some studies on the capacity of the greenery apparatus to decrease wind speed and regulate temperatures with the combination of the moisture retained by the plants and the air passing through them, but there is little on the maintenance of performance under particular weather conditions. The aim of this contribution is to verify the effectiveness of a vegetal façade in particularly windy conditions combined with rainy and/or high-irradiation events. The subject of the study is the enclosure of the Technology Innovation Centre for Development (itdUPM), on the Polytechnic University of Madrid, where a green wall prototype has been installed. For the purposes of the analysis, the environmental variables are examined and the monitoring data received from sensors positioned at the walls and skin of the insulated envelope are compared with the green face and without, comparing the differences in surface temperatures. These analyses are further examined by considering the correlation with different weather conditions. Experimentation shows a maintenance of performance, retaining an insulating capacity in all seasons, in both wind and rain, with results more evident in daylight hours. This contribute want to analyse the subtle variance between the performance of south and west facades. The strongest effect came forward during the summer season because the wall is affected by continuous irradiation on the south that is, also increased by hot weather.

The Effect of Surface Oil on Ocean Wind Stress

This study provides, to the best of our knowledge, the first detailed analysis of how surface oil modifies air–sea interactions in a two-way coupled model, i.e., the coupled–ocean–atmosphere–wave–sediment–transport (COAWST) model, modified to account for oil-related changes in air–sea fluxes. This study investigates the effects of oil on surface roughness, surface wind, surface and near-surface temperature differences, and boundary-layer stability and how those conditions ultimately affect surface stress. We first conducted twin-coupled modeling simulations with and without the influence of oil over the Deepwater Horizon (DWH) oil spill period (20 April to 5 May 2010) in the Gulf of Mexico. Then, we compared the results by using a modularized flux model with parameterizations selected to match those selected in the coupled model adapted to either ignore or account for different atmospheric/oceanic processes in calculating surface stress. When non-oil inputs to the bulk formula were treated as being unchanged by oil, the surface stress changes were always negative because of oil-related dampening of the surface roughness alone. However, the oil-related changes to 10 m wind speeds and boundary-layer stability were found to play a dominant role in surface stress changes relative to those due to the oil-related surface roughness changes, highlighting that most of the changes in surface stress were due to oil-related changes in wind speed and boundary-layer stability. Finally, the oil-related changes in surface stress due to the combined oil-related changes in surface roughness, surface wind, and boundary-layer stability were not large enough to have a major impact on the surface current and surface oil transport, indicating that the feedback from the surface oil to the surface oil movement itself is insignificant in forecasting surface oil transport unless the fractional oil coverage is much larger than the value found in this study.

A comparative analysis of the sea breeze on the Texas Gulf Coast and its impact on precipitation

An analysis of the sea breeze, its mechanisms and correlation with precipitation was performed in two cases for an urban city on the Gulf Coast where the first case examined pure sea breezes and the second investigated those associated with a likelihood for appreciable inland precipitation. Adjacent study areas to the east and west were used as background conditions to determine if changes in Houston's sea breeze are controlled by urbanization or climate change. Sea breeze days were selected by a three-filter algorithm using the difference in land and sea surface temperatures, ΔTSB, as well as geostrophic and surface winds. Results showed a decrease of 3–21% in sea breeze days between cases in the Houston area. Case 2 exhibited the most (e.g., 524 sea breeze days) and greatest increase (0.63 day yr−1) in sea breeze days in Beaumont, driven by an increase in land surface temperature which is statistically significant (p-value = 0.02) and decrease in sea surface temperature leading to an increase in ΔTSB, again with statistical significance (p-value = 0.01). Precipitation has increased by at least 1.07 × 10−8 mm day−1, with the greatest increase of 2.59 × 10−8 mm day−1 in Beaumont. The only increase in precipitation that was not found to be statistically significant existed for the most inland station in Houston. Based on an areal analysis of land cover, Houston is significantly more urban than the adjacent study areas: 65.8% of its area falls into the four developed classes, and these classes have increased by 11.4% between 2001 and 2019. Comparatively, Beaumont and Victoria are 16.8% and 7.16% developed, and urban development increased by 1.20% and 0.61%, respectively, over the same period. This indicates the possibility that the roughness elements in Houston's built environment interfere with the sea breeze, while climate change has driven its increase in Beaumont and decrease in Victoria as evidenced by our reported changes in meteorological variables.

Genome-wide evolutionary signatures of climate adaptation in spotted sea bass inhabiting different latitudinal regions.

Consideration of the thermal adaptation of species is essential in both evolutionary biology and climate-change biology because it frequently leads to latitudinal gradients of various phenotypes among populations. The spotted sea bass (Lateolabrax maculatus) has a broad latitudinal distribution range along the marginal seas of the Northwest Pacific and thus provides an excellent teleost model for population genetic and climate adaptation studies. We generated over 8.57 million SNP loci using whole-genome resequencing from 100 samples collected at 14 geographic sites (five or ten samples per site). We estimated the genetic structure of the sampled fish and clustered them into three highly differentiated populations. The genetic differentiation pattern estimated by multivariable models combining geographic distance and sea surface temperature differences suggests that isolation by distance and isolation by environment both have significant effects on this species. Further investigation of genome-wide evolutionary signatures of climate adaptation identified many genes related to growth, muscle contraction, and vision that are under positive natural selection. Moreover, the contrasting patterns of natural selection in high-latitude and low-latitude populations prompted different strategies of trade-offs between growth rate and other traits that may play an essential role in adaptation to different local climates. Our results offer an opportunity to better understand the genetic basis of the phenotypic variation in eurythermal fishes inhabiting different climatic regions.

The specificity of body surface temperature of relevant back-shu points in patients with chronic persistent asthma based on infrared thermal imaging technology

To detect the body surface temperature of the relevant back-shu points in patients with chronic persistent asthma by infrared thermal imaging technology, and observe the specific changes of the body surface temperature of the relevant back-shu points under the condition of lung disease. Forty-five patients with chronic persistent asthma (observation group) and 45 healthy subjects (control group) were selected. The body surface temperature of bilateral Feishu (BL 13), Geshu (BL 17), Pishu (BL 20) and Shenshu (BL 23) were measured by BK-MT02A medical infrared thermography. The body surface temperature of bilateral Feishu (BL 13), Geshu (BL 17), Pishu (BL 20) and Shenshu (BL 23) in the observation group was higher than that in the control group (P<0.01, P<0.05). The body surface temperature of bilateral Feishu (BL 13) and Geshu (BL 17) was higher than that of ipsilateral Pishu (BL 20) and Shenshu (BL 23) in the two groups (P<0.01, P<0.05). There was no statistically significant difference in body surface temperature between ipsilateral Feishu (BL 13) and Geshu (BL 17), between ipsilateral Pishu (BL 20) and Shenshu (BL 23) (P>0.05). The pathological increase of body surface temperature of Feishu (BL 13), Geshu (BL 17), Pishu (BL 20) and Shenshu (BL 23) in patients with chronic persistent asthma indicates that above acupoints have specificity in reflecting lung diseases. The Feishu (BL 13) and Geshu (BL 17), which have significantly increased body surface temperature, not only provide objective basis for the pathological pathogenesis of "deficiency in origin and excess in symptom" in patients with chronic persistent asthma, but also reflect the different expressions of different acupoints on the same meridian for the lung diseases.

Numerical investigation of organic fluid flow boiling for proton exchange membrane fuel cell cooling and waste heat recovery

High power density is one of the competitive edges of proton exchange membrane fuel cell (PEMFC), making it a promising technology for many applications. However, its intensive heat generation leads to a high cooling burden, and a large amount of low-grade waste heat is difficult to utilize, which brings technical difficulty to the system's thermal management. In this study, the organic fluid (R245fa) with low boiling temperature is selected for the PEMFC stack's phase change cooling, and the organic Rankine cycle (ORC) is employed to recover waste heat. Four cooling channels are designed: serpentine straight, spiral straight, serpentine thin and serpentine zigzag channels. The boiling flow is simulated to reveal the effect of channel layout, sectional size and channel shape on the cooling and heat recovery performance. The results show that the cooling plates can be cooled to a reasonable temperature by the organic fluid, and the maximum surface temperature difference is within 15 K, which demonstrates the good cooling performance of flow boiling. The highest ORC thermal efficiency of 7% is achieved by the serpentine straight channel and the spiral straight channel, while the serpentine zigzag channel has the best temperature uniformity contribution resulting from its secondary circulation flow. This study demonstrates the potential of flow boiling on PEMFC thermal management and gives guidance on the cooling channel design.

Application of Multi-Temporal Landsat Images to Analyze the Relationship Between the Land Surface Temperature (LST) and the Land Use Land Cover (LULC) in Ho Chi Minh City

Urban sprawl has changed the land use land cover (LULC) in Ho Chi Minh City (HCMC). It has caused the gradual decline of the natural vegetation and rapid increase of the impervious surface, which leads to the heat storage capacity of the urban surface being on the rise. There is a land surface temperature (LST) difference between the urban center and surrounding areas and it creates the urban heat island phenomenon (UHI). This study used Landsat 4, 5, and Landsat 8 satellite image data from 1990 to 2020 with the GIS algorithms on ENVI and ArcGIS to analyze and estimate the correlation between the LULC and the LST in HCMC. The Kappa coefficients of the LULC classifications were all over 0.8 in 1990 – 2020 period. The total area of impervious surface has increased by 57,338 hectares over the past 30 years; while the total area of natural green has decreased by 19,116 hectares. The LST has remarkably increased in the areas of construction lands, industrial zones, and impervious surfaces, with an average increase from 22°C to 27°C. While the LST in the others such as the vegetation surface and water surface were slower, from 20°C to 23°C. The solution of enhancing the urban green space was suggested to mitigate the increasing LST impact on HCMC.

The Representative Thermal Conductivity of Wickless Heat Pipes in a Thermoelectric Generator Module Design via Computational Numerical Analysis

Thermoelectric generator (TEG) cells are capable of producing electricity from the flow of heat through semiconductor materials via the Seebeck effect. A TEG module (TEM) was developed through the integration of TEG cells, heat pipes, and heat sinks with the function to recover low-temperature waste heat for combined heat and power outputs. The mechanics of heat transport through the components have a distinctive impact on overall performance. Wickless heat pipes were used in the design, and it is difficult to directly evaluate the convection heat transfer coefficient within the heat pipes. Computational numerical analysis usually simplifies the heat pipe by modelling it as a solid copper pipe, where the thermal conductivity of the pipe replaces the actual value of heat transfer coefficient. To determine the representative thermal conductivity of the wickless heat pipe, a computational numerical model of the TEM was developed. Experiment data of the TEM operation, where the cold-side air inlet temperature inlet was at 20.7°C while the hot-side waste heat inlet temperature was at 70.0°C, was used to validate the computational model. The representative thermal conductivity value for the wickless heat pipe was found to be 500 W/m.K, at which the percentage difference for the hot-side and cold-side TEG surface temperatures, and the TEG surface temperature differences were below 5%. The approach has been proven suitable to analyse the representative heat pipe thermal conductivity for simplified thermoelectric generator modules.