Tao Lin^1,*, Chengdai Chen¹, Liyao Chen¹, Fengqin Han¹, Guanghui He²

Frontiers in Heat and Mass Transfer, Vol.23, No.5, pp. 1661-1680, 2025, DOI:10.32604/fhmt.2025.070787 - 31 October 2025

Abstract Targeting spontaneous coal combustion during stacking, we developed an efficient heat dissipation & self-supplied wireless temperature measurement system (SPWTM) with gravity heat pipe-thermoelectric integration for dual safety. The heat transfer characteristics and temperature measurement optimization of the system are experimentally investigated and verified in practical applications. The results show that, firstly, the effects of coal pile heat production power and burial depth, along with heat pipe startup and heat transfer characteristics. At 60 cm burial depth, the condensation section dissipates 98% coal pile heat via natural convection. Secondly, for the temperature measurement error caused by… More >

Rafah H. Zaidan^*, Najim A. Jasim

Frontiers in Heat and Mass Transfer, Vol.23, No.5, pp. 1595-1620, 2025, DOI:10.32604/fhmt.2025.068205 - 31 October 2025

Abstract This paper presents a comprehensive experimental and numerical investigation of radiant floor heating (RFH) systems integrated with phase change material (PCM)-based thermal energy storage (TES). The study compares two underfloor pipe configurations: double serpentine and spiral. It also looks at how well a paraffin wax PCM system works with compact heat exchanger-type TES units during winter in Iraq. Key performance indicators including discharge temperature, heat transfer rate, liquid fraction evolution, and temperature uniformity were assessed through in situ experimental measurements and ANSYS fluent simulations. Results demonstrate that the spiral design provides slightly more uniform temperature distribution… More >

Leonid Plotnikov^*

Frontiers in Heat and Mass Transfer, Vol.23, No.5, pp. 1443-1454, 2025, DOI:10.32604/fhmt.2025.068060 - 31 October 2025

Abstract Industry and energy continue to require piston engines (PICE) at a high level worldwide. Therefore, science and technology must urgently work on improving the PICE working cycle. Improving the quality of the intake process of the working fluid into the cylinder is one of the most effective ways to improve the operational performance of PICE. The purpose of the study was to assess the impact of various cylinder head (CylH) designs on the gas-dynamic and heat-exchange qualities of air flows within an engine model’s intake system. Three different CylH designs were studied: the basic configuration… More >

Federico Sacchelli¹, Luca Cattani^1,2, Matteo Malavasi¹, Fabio Bozzoli^1,2,*, Corrado Sciancalepore¹

Frontiers in Heat and Mass Transfer, Vol.23, No.5, pp. 1351-1364, 2025, DOI:10.32604/fhmt.2025.064154 - 31 October 2025

Abstract This study investigates the feasibility of a novel dual two-phase cooling system for thermal management in lithium-ion batteries used in electric vehicles (EVs). The proposed system aims to combine low-boiling dielectric fluid immersion cooling and pulsating heat pipes (PHPs), in order to leverage the advantages of both technologies for efficient heat dissipation in a completely passive configuration. Experimental evaluations conducted under different discharge conditions demonstrate that the system effectively maintains battery temperatures within the optimal range of 20–40°C, with enhanced temperature uniformity and stability. While the PHP exhibited minimal impact at low power, its role More >

Xin Liu¹, Zheng Zhang^2,*, Yu Zhao³, Yi Yang², Zhenning Qiao², Zhibo Xu², Xianzhi Yu²

Energy Engineering, Vol.122, No.11, pp. 4679-4702, 2025, DOI:10.32604/ee.2025.068371 - 27 October 2025

Abstract With the growing demand for offshore energy, deepwater drilling has become a vital technology in petroleum engineering. However, conventional drilling systems often face limitations such as delayed bottomhole pressure response and low control precision, particularly under narrow pressure window and complex formation conditions. To address these challenges, Dual-layer Pipe dual-gradient drilling (DGD) technology has been introduced, utilizing a dual-pipe structure and downhole lift pumps to extend the pressure control range. Despite these advantages, current DGD systems lack fast and precise bottomhole pressure control due to their reliance on indirect flow-based methods. This study proposes a… More >

Ali Abdulshaheed^1,*, Faizal Mustapha¹, Mohd Anuar²

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.9, pp. 2289-2304, 2025, DOI:10.32604/fdmp.2025.066983 - 30 September 2025

Abstract A pump operating as a turbine (PAT) is a type of hydraulic machine capable of functioning both as a pump and as a turbine by reversing the flow direction. The pump-as-turbine (PAT) approach presents an effective method of hydropower generation, particularly suitable for addressing the increasing global energy demands in rural and remote areas. In addition to its adaptability, PAT-based micro-hydropower systems typically incur lower operating costs than conventional hydrodynamic turbines, despite requiring higher initial investment. Recent research has focused on integrating PATs into pipe distribution systems to harness untapped hydraulic energy. This study presents… More >

Jinping Xu^1,2, Zhiyun Wang¹, Mo Yang^1,*

Frontiers in Heat and Mass Transfer, Vol.23, No.4, pp. 1151-1163, 2025, DOI:10.32604/fhmt.2025.067925 - 29 August 2025

Abstract In concentric annular pipes, the difference in curvature between the inner and outer wall surfaces creates significant variations in the heat transfer characteristics of the two surfaces. The simplifications of the Dittus-Boelter equation for circular pipes make it unsuitable for the complex flow induced by the geometry and heat transfer coupling effects in annular pipes. This prevents it from accurately predicting the turbulent heat transfer in concentric annular pipes. This paper used realizable κ–ε and low Reynolds number models to conduct numerical simulations of turbulent convective heat transfer in concentric annular pipes and circular pipes.… More >

Chuxin Wang, Qi Wu, Zenong Fang, Chang Liu, Guoguang Li, Ye Wang, Hongxing Zhang^*, Jianyin Miao

Frontiers in Heat and Mass Transfer, Vol.23, No.4, pp. 1261-1280, 2025, DOI:10.32604/fhmt.2025.066473 - 29 August 2025

Abstract With the development of space-based remote sensing and deep space exploration technology, higher standards for temperature stability and uniformity of payloads have been proposed to spacecraft thermal control systems. As an efficient two-phase heat transfer device with active temperature control capabilities, the loop heat pipe (LHP) can be widely applied in spacecraft thermal control systems to achieve reliable temperature control under various operating modes and complex space thermal environments. This paper analyzes the fundamental theories of thermal switch-controlled, reservoir temperature-controlled, and bypass valve-controlled LHPs. The focus is on the theories and methods of achieving high-precision… More >

Miao Li^1,2,*, Xiaojun Li^1,3, Mingyang Zhao^1,2

CMC-Computers, Materials & Continua, Vol.85, No.1, pp. 1917-1936, 2025, DOI:10.32604/cmc.2025.067382 - 29 August 2025

Abstract Aiming at problems such as large errors and low efficiency in manual counting of drill pipes during drilling depth measurement, an intelligent detection and counting method for the small targets at the end of drill pipes based on the improved YOLO11n is proposed. This method realizes the high-precision detection of targets at drill pipe ends in the image by optimizing the target detection model, and combines a post-processing correction mechanism to improve the drill pipe counting accuracy. In order to alleviate the low-precision problem of YOLO11n algorithm for small target recognition in the complex underground… More >

Asaad Algarni¹, Iqra Aijaz Abro², Mohammed Alshehri³, Yahya AlQahtani⁴, Abdulmonem Alshahrani⁴, Hui Liu^5,*

CMC-Computers, Materials & Continua, Vol.84, No.3, pp. 5879-5896, 2025, DOI:10.32604/cmc.2025.064601 - 30 July 2025

Abstract Inertial Sensor-based Daily Activity Recognition (IS-DAR) requires adaptable, data-efficient methods for effective multi-sensor use. This study presents an advanced detection system using body-worn sensors to accurately recognize activities. A structured pipeline enhances IS-DAR by applying signal preprocessing, feature extraction and optimization, followed by classification. Before segmentation, a Chebyshev filter removes noise, and Blackman windowing improves signal representation. Discriminative features—Gaussian Mixture Model (GMM) with Mel-Frequency Cepstral Coefficients (MFCC), spectral entropy, quaternion-based features, and Gammatone Cepstral Coefficients (GCC)—are fused to expand the feature space. Unlike existing approaches, the proposed IS-DAR system uniquely integrates diverse handcrafted features using… More >