http://yetl.yabesh.ir/yetl1/handle/yetl/19052 2026-04-22T16:57:08Z 2026-04-22T16:57:08Z Gao, Jiayang Zhang, Lei http://yetl.yabesh.ir/yetl1/handle/yetl/4311045 2026-02-17T22:02:56Z 2025-01-01T00:00:00Z

Design of Encapsulated Phase Change Material Cooling Scheme for Compact 21700 Battery Modules Gao, Jiayang; Zhang, Lei This article proposes a versatile thermal management solution utilizing phase change material (PCM) for compact 21700 battery modules. First, a flame-retardant and heat-conductive pouring sealant is utilized to encapsulate the PCM. The impact of the diameter and number of PCM columns on the thermal performance of the battery module is evaluated by single-factor and multi-objective optimization methods. Then, a low-temperature heating scheme utilizing film heaters is devised for the battery module. The results indicate that the heat generation of the battery diminishes as the working temperature rises, whereas it escalates with an increase in the discharge rate. When the number of PCM columns is 8 and the inner and outer heights are 66 mm and 13 mm, the maximum temperature and the temperature difference of the battery module are controlled at 45.6 °C and 4.61 °C, respectively. With a heating film power of 13.6 W, the average temperature of the battery module may increase from −5 °C to 11.7 °C in 25 min, resulting in a temperature differential of 4.6 °C.

2025-01-01T00:00:00Z Arora, Amit Subbarao, P. M. V. http://yetl.yabesh.ir/yetl1/handle/yetl/4311044 2026-02-17T22:02:53Z 2025-01-01T00:00:00Z

Wake Management and Capacity Augmentation by Toe-Out Type Vortex Generators in Finned-Tube Heat Exchangers Arora, Amit; Subbarao, P. M. V. Waste heat recovery usually involves indirect heat transfer, between two fluids, across a diathermic wall; and finned-type recuperative heat exchangers are preferred for the stipulated task. Strategic integration of vortex generators in aforesaid systems produces such flow structures which greatly improve the effectiveness of the heat exchanger. Often heat exchanger designers place generators at under-performing locations, despite knowing the best ones, due to manufacturing restrictions. Since the generators' geometry too affects the thermal augmentation, positional compromise can be duly compensated. This study uses a computational analysis to investigate the effect of varying the geometric aspect ratio of the generators. For a conclusive assessment of the geometric designs, the attack angles espoused for integrating the generators cater to the entire effective range. In order to understand the changes in flow characteristics, velocity fields are examined which suggests that reducing the generators' aspect ratio aids in diverting the oncoming flow, and so limits the tube wake zones. Additionally, the swirling flow generated by the vortex generators facilitates bulk mixing across a large fin surface. Both flow modifications together give a substantial boost to the thermal performance, thereby downsizing the system.

2025-01-01T00:00:00Z Liu, Yajiao Lv, Yuzheng Zhao, Yu Xiong, Ye http://yetl.yabesh.ir/yetl1/handle/yetl/4310985 2026-02-17T22:00:33Z 2025-01-01T00:00:00Z

Experimental and Numerical Investigations on Thermal Interference of the Helix Ground Heat Exchanger for Ground Source Heat Pump System Liu, Yajiao; Lv, Yuzheng; Zhao, Yu; Xiong, Ye This study conducted an investigation on the heat transfer process of helix ground heat exchanger (HGHE) by numerical simulation and experiment. The concept of thermal interference index was proposed, and the thermal interference index in the soil around HGHE was investigated under different soil type conditions. The results showed that with the progress of the heat transfer process of the HGHE, the thermal interference of the soil around the HGHE gradually increases. Therefore, the transient heat transfer coefficient and efficiency coefficient of the HGHE decrease, which weakens the heat exchange between the HGHE and the soil to a certain extent. When burying the HGHE, priority should be given to the soil type with excellent thermal conductivity, which is conducive to the outward diffusion of heat emission from the heat exchanger. In this way, it can effectively reduce the thermal interference index of the soil around the HGHE and can indirectly improve the heat transfer performance of the heat exchanger. For example, in sandy loam soil type condition, the thermal interference at the middle of the busbar position is 2.14 (m·°C)/W, which is 83.3% of the clay loam soil type condition. Therefore, the heat flux of HGHE under sandy loam condition is about 20.7% higher than that under clay loam condition.

2025-01-01T00:00:00Z Zhou, Chenglin Zhou, Liqun http://yetl.yabesh.ir/yetl1/handle/yetl/4310981 2026-02-17T22:00:24Z 2025-01-01T00:00:00Z

Stochastic Modeling and Numerical Simulation of Carbon Fiber Felt for Effective Thermal Conductivity Considering Radiation Heat Transfer Zhou, Chenglin; Zhou, Liqun Carbon fiber felt (CFF) has excellent thermal insulation ability under high-temperature environments. In this study, an algorithm for generating CFF microstructure models was developed. The heat transfer characteristic of the CFF is studied based on the computational fluid dynamics (CFD) theory coupling Monte Carlo method. The influence of different temperature variation, porosity, and fiber arrangement on the effective thermal conductivity is investigated. The result indicates that the effective thermal conductivity decreases with the increase of disorder in fiber arrangement. In addition, there is a negative correlation between the effective thermal conductivity and porosity. Furthermore, the impact of radiant heat transfer is evaluated. The radiative thermal conductivity rises in accordance with the augmentation of porosity, which accounts for 13–39% of the total thermal conductivity. The study can provide a theoretical framework for the prediction of the thermal behavior of CFF in thermal environments.

2025-01-01T00:00:00Z