Liang Yi, Zhiqiang Lei, Zhisheng Xu, Yaolong Yin, Houlin Ying^*

Frontiers in Heat and Mass Transfer, Vol.22, No.4, pp. 977-996, 2024, DOI:10.32604/fhmt.2024.053688 - 30 August 2024

Abstract This paper explores the smoke flow characteristics in tunnel fires, giving a particular emphasis on the effects of different distances between the smoke outlets and the fire source. It examines the smoke behavior under different conditions, including variations in heat release rates, exhaust volumetric flow rates, spacing between smoke outlets, and the longitudinal fire source positions. Results indicate that altering the fire source positions and the smoke outlets in the tunnel leads to variations in the properties of smoke flow both the fire source upstream and downstream; the distance between fire source and smoke outlet… More > Graphic Abstract

Long Yu, Dongdong Pang^*, Minmin She, Hongwei Qiu, Ping Cao, Xiongwei You

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.8, pp. 1823-1846, 2024, DOI:10.32604/fdmp.2024.048093 - 06 August 2024

Abstract In this study, the motion of wet particles in the drying unit of a vertical powder dryer is investigated by using a Discrete element method (DEM) coupled with a liquid bridge force. In particular, by varying parameters such as the particle mass flow rates, the superficial gas velocities, and superficial gas temperatures, the influence of the moisture content on the flow behavior is examined. The results show that when the moisture content increases, the mean particle velocity decreases while the bed mean solid “holdup” and the mean residence time (MRT) of particles grow. It is More > Graphic Abstract

Yun Ren^1,*, Lianzheng Zhao², Xiaofan Mo², Shuihua Zheng², Youdong Yang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.7, pp. 1593-1609, 2024, DOI:10.32604/fdmp.2024.046274 - 23 July 2024

Abstract A coupled Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) approach is used to calculate the interaction of a flexible rag transported by a fluid current with a fixed solid cylinder. More specifically a hybrid Eulerian-Lagrangian approach is used with the rag being modeled as a set of interconnected particles. The influence of various parameters is considered, namely the inlet velocity (1.5, 2.0, and 2.5 m/s, respectively), the angle formed by the initially straight rag with the flow direction (45°, 60° and 90°, respectively), and the inlet position (90, 100, and 110 mm, respectively). The results show More > Graphic Abstract

Bo Hui^1,2,*, Shengneng Zhu², Sijun Su², Wenjuan Li²

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 855-868, 2024, DOI:10.32604/fhmt.2024.051387 - 11 July 2024

Abstract The structure of the concave-convex plates has proven to be crucial in optimizing the internal flow characteristics of the electrolyzer for hydrogen production. This paper investigates the impact of the gradual expansion angle of the inlet channel on the internal flow field of alkaline electrolyzers. The flow distribution characteristics of concave-convex plates with different inlet angle structures in the electrolytic cell is discussed. Besides, the system with internal heat source is studied. The results indicate that a moderate gradual expansion angle is beneficial for enhancing fluid uniformity. However, an excessively large gradual expansion angle may More > Graphic Abstract

Husam Rashid Hudear^*, Saad Najeeb Shehab

Frontiers in Heat and Mass Transfer, Vol.21, pp. 367-383, 2023, DOI:10.32604/fhmt.2023.042639 - 30 November 2023

Abstract This paper presents a numerical emulation study of heat transmission through tube banks in three-dimensions. Staggered configuration is displayed by fluid dynamics using computer programs (CFD) software (ANSYS fluent). The computer model is used to predict the values of the Nusselt number when changing the values of heat flux and longitudinal pitch. The longitudinal pitch (SL/D) of 1.3, 1.8, and 2.4 mm. The transverse pitch (ST/D) of 1.5 mm, and also considered Reynolds numbers 10000, 13000, 17000, and 190000. The staggered configuration of the tube bundle is demonstrated to investigate the impact of this arrangement More >

Chun Ye^1,2,3, Jingjing Gao^1,2,3, Zhihui Wang^1,2,3, Weibiao Zheng^1,2,3, Yibei Wang^2,4, Xingkai Zhang^1,2,3,*, Ming Liu⁵

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.3, pp. 755-766, 2023, DOI:10.32604/fdmp.2022.021868 - 29 September 2022

Abstract The response of an adjustable critical-flow Venturi nozzle is investigated through a set indoor experiments aimed to determine the related critical flow rate, critical pressure ratio, and discharge coefficient. The effect of a variation in the cone displacement and liquid content on the critical flow characteristics is examined in detail and it is shown that the former can be used to effectively adjust the critical flow rate. The critical pressure ratio of the considered nozzle is above 0.85, and the critical flow control deviation of the gas flow is within ±3%. Liquid flow can reduce More >

Ting Zhang¹, Denghao Wu^1,2,*, Shijun Qiu², Peijian Zhou¹, Yun Ren³, Jiegang Mou¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.5, pp. 1349-1361, 2022, DOI:10.32604/fdmp.2022.019617 - 27 May 2022

Abstract Stall phenomena increase the complexity of the internal flow in centrifugal pump impellers. In order to tackle this problem, in the present work, a large eddy simulation (LES) approach is applied to determine the characteristics of these unstable flows. Moreover, a vorticity identification method is used to characterize quantitatively the vortex position inside the impeller and its influencing area. By comparing the outcomes of the numerical simulations and experimental results provided by a Particle Image Velocimetry (PIV) technique, it is shown that an apparent “alternating stall” phenomenon exists inside the impeller when relatively small flow More >

Yajuan Jia¹, Lisha Shang¹, Jiangping Nan¹, Guangping Hu², Zhigang Fang^3,4,*

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 329-344, 2022, DOI:10.32604/fdmp.2022.017734 - 16 December 2021

Abstract The flow past a fixed single transmission conductor and the related heat transfer characteristics are investigated using computational fluid dynamics and a relevant turbulence model. After validating the method through comparison with relevant results in the literature, this thermofluid-dynamic problem is addressed considering different working conditions. It is shown that the resistance coefficient depends on the Reynolds number. As expected, the Nusselt number is also affected by Reynolds number. In particular, the Nusselt number under constant heat flux is always greater than that under a constant wall temperature. More >

Xiaosai Duan, Suihuai Yu^*, Jianjie Chu, Dengkai Chen and Zhaojing Su

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.2, pp. 701-721, 2022, DOI:10.32604/cmes.2022.016779 - 13 December 2021

Abstract The rational design of airflow distribution is of great importance for comfort and energy conservation. Several numerical investigations of flow and temperature characteristics in cockpits have been performed to study the distinct airflow distribution. This study developed the coupled heat transfer model of radiation, convection, and heat conduction for the cockpit flight environment. A three-dimensional physical model was created and a shear stress transfer (SST) k-w turbulence model was well verified with a high prediction accuracy of 91% for the experimental data. The strong inhomogeneous flow and temperature distribution were captured for various initial operating… More >

Senchun Miao^1,2,*, Hongbiao Zhang¹, Wanglong Tian¹, Yinqiang Li²

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.6, pp. 1021-1036, 2021, DOI:10.32604/fdmp.2021.016925 - 08 September 2021

Abstract To study the unsteady flow and related energy conversion process in the volute of a pump-as-turbine (PAT) device, six different working conditions have been considered. Through numerical calculation, the spatio-temporal variation of static pressure, dynamic pressure, total pressure and turbulent energy dissipation have been determined in each section of the volute. It is concluded that the reduction of the total power of two adjacent sections of the PAT volute is equal to the sum of the power lost by the fluid while moving from one section to the other and the power output from the More >