Xiao Sun^a, Fan-Kang Zeng^a, Jia-Bing Yang^a, Feng-Lin Zhou^a, Yu-Liang Zhang^b,*

Frontiers in Heat and Mass Transfer, Vol.17, No.1, pp. 1-6, 2021, DOI:10.5098/hmt.17.5

Abstract In order to better study the internal flow characteristics of centrifugal pump as turbine, CFX software is employed to carry out numerical simulation to obtain flow field under different working conditions for pump as turbine based on the standard k - epsilon turbulence model and the SIMPLEC algorithm. The efficiency curves of the pump and pump as turbine are obtained under different working conditions. The results show that the effciency characteristics of the pump change greatly during the process of pumping. The efficiency of the turbine is higher than that of the pump under the respective optimal operating conditions. The… 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

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 the gas critical mass flow… 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

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 rate conditions are considered. The… More >

Shuang Zhao^1,2,3, Xijun Li⁴, Jianwen Wang^1,2,3,*

Energy Engineering, Vol.119, No.4, pp. 1379-1392, 2022, DOI:10.32604/ee.2022.019776

Abstract The computational fluid dynamics method was used to simulate the flow field around a wind turbine at the yaw angles of 0°, 15°, 30°, and 45°. The angle of attack and the relative velocity of the spanwise sections of the blade were extracted with the reference points method. By analyzing the pressure distribution and the flow characteristics of the blade surface, the flow mechanism of the blade surface in the yawed condition was discussed. The results showed that the variations of the angle of attack and the relative velocity were related to the azimuth angle and the radius in the… 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

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

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 conditions (inlet temperature, inlet pressure,… More >

Shaohua Zhai¹, Guannan Xi^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.1, pp. 109-130, 2022, DOI:10.32604/fdmp.2022.018186

Abstract In order to study the effect of different gap ratios on the thermofluid-dynamic field around a bluff body located in proximity to a heated wall, a series of experiments and numerical simulations have been conducted. The former were carried out using an open circulating water tank experimental platform and a single cylinder and square column as geometrical models (their characteristic length being D). The latter were based on the well-known SIMPLE algorithm for incompressible flow. The results show that the gap ratio is an important factor affecting the wake characteristics of near-wall bluff bodies. When the gap ratio is small,… 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

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 two adjacent sections. For a… More >

Huinan Sun^1,*, Siqiang Wang², Zhuoqing Zhang¹, Chaoyong Xia¹, Xu Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 855-873, 2021, DOI:10.32604/cmes.2021.015791

Abstract Grains are widely present in industrial productions and processing, and are stored in silos. In the silo, auxiliary structures are added to achieve efficient production. However, little effort has been devoted to the influence of the internal structure of the silo on the granular flow. In this work, a silo with a central decompression tube is studied through experimental measurements and discrete element methods. Then, the influences of the central decompression tube on the flow behavior of grains and wall pressure are analyzed. Results show that the grains are in mass flow in the silo without a central decompression tube,… More >

Yukun Lv, Quanzhi Ge^*, Zhuang Wei, Shuang Yang

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.4, pp. 833-844, 2021, DOI:10.32604/fdmp.2021.015082

Abstract The splitter is an important component of water-based cooling systems used to extract heat from computer boards. In the present study, the flow characteristics of a 16-splitter structure were numerically simulated and compared with experimental results to verify the reliability of the numerical simulation method. Accordingly, the concept of splitter structural coefficients was proposed. Based on the results of this study, we recommend a selection range of 5 ≤ k ≤ 6 for the structure factor k of the splitter; after optimization, the maximum deviation of the splitter outlet flow was reduced from the original value of 100% to 8.3%. More >