Liying Zhou^1,2, Yu Liang^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 159-170, 2021, DOI:10.32604/fdmp.2021.010051

Abstract The use of ethanol is a promising method to reduce the emissions of diesel engines. The present study has been based on the installation of a gasoline electronic injection system in a single-cylinder diesel engine to control the amount of ethanol entering the cylinder during the compression (while diesel has been injected into the cylinder by the original pump injection system). The injection time has been controlled by crank angle signal collected by an AVL angle indicator. In the tests ethanol and diesel each accounted for half of the fuel volume, and the total heat energy supply of the fuel… More >

Miao Xin, Guo Zhong, Yihua Cao^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1063-1092, 2020, DOI:10.32604/fdmp.2020.013378

Abstract A numerical method for the analysis of the electrothermal deicing system for an airfoil is developed taking into account mass and heat exchange at the moving boundary that separates the water film created due to droplet impingement and the ice accretion region. The method relies on a Eulerian approach (used to capture droplet dynamics) and an unsteady heat transfer model (specifically conceived for a multilayer electrothermal problem on the basis of the enthalpy theory and a phase-change correction approach). Through application of the continuous boundary condition for temperature and heat flux at the coupled movingboundary, several simulations of ice accretion,… More >

Ioannis Oxyzoglou^*, Zheng-Tong Xie

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1093-1114, 2020, DOI:10.32604/fdmp.2020.012237

Abstract The broad implication of the paper is to elucidate the significance of the dynamic heaving motion in the aerodynamic performance of multi-element wings, currently considered as a promising aspect for the improvement of the aerodynamic correlation between CFD, wind tunnel and track testing in race car applications. The relationship between the varying aerodynamic forces, the vortex shedding, and the unsteady pressure field of a heaving double-element wing is investigated for a range of mean ride heights, frequencies, and amplitudes, using a two-dimensional (2D) unsteady Reynolds-averaged Navier-Stokes (URANS) approach and an overset mesh method for modelling the moving wing. The analysis… More >

Shan Jin^1,2,3, Xiaohong Bai⁴, Wei Luo^1,2,3,*, Li Li⁴, Ruiquan Liao^1,2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1229-1242, 2020, DOI:10.32604/fdmp.2020.011051

Abstract With the increasing number of horizontal wells with low pressure, low yield, and water production, the phenomenon of water and liquid accumulation in gas wells is becoming progressively more serious. In order to fix these issues, it is necessary to improve existing drainage and gas recovery technologies, increase the fluid carrying capacity of these wells, and ensure that the bottom-hole airflow has enough energy to transport the liquid to the wellhead. Among the many techniques of drainage and gas recovery, the gas lift has recently become a popular method. In the present study, through the simulation of the entire horizontal… More >

Daoming Shen^1,*, Xia Zhang¹, Wei He¹, Jinhong Xia¹, Songtao Xue²

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1259-1272, 2020, DOI:10.32604/fdmp.2020.010951

Abstract Experiments about heat transfer in the presence of a two-phase flow due to the condensation of a R1234yf refrigerant have been performed considering a smooth tube and two micro-fin tubes. The following experimental conditions have been considered: Condensation temperatures of 40°C, 43°C and 45°C, mass fluxes of 500–900 kg/(m² ·s), vapor qualities at the inlet and outlet of the heat transfer tube in the ranges 0.8–0.9 and 0.2–0.3, respectively. These tests have shown that: (1) The heat transfer coefficient increases with decreasing the condensation temperature and on increasing the mass flux; (2) The heat transfer coeffi- cient inside the micro-fin… More >

Liang Ce, Yongchen Pan^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1115-1128, 2020, DOI:10.32604/fdmp.2020.010829

Abstract Two flow cases for scaled high speed train models with different length are numerically analyzed in the framework of the improved delayed detachededdy simulation model. Specific attention is paid to the shear flows and related mechanisms in the near turbulent wake created by these moving models. In particular, a comparative analysis is made on the distributions of turbulent kinetic energy (TKE) and turbulence production (TP) in planes perpendicular to the streamwise direction. The numerical results suggest that, in the wake region very close to the tail, significant TKE and TP can be ascribed to the dynamic interaction between powerful eddies… More >

Jinbo Liu¹, Ziheng Jiang², Xuezhang Feng¹, Ruiquan Liao², Dianfang Feng¹, Xingkai Zhang^2,*, Hasimu Aikeremu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1243-1258, 2020, DOI:10.32604/fdmp.2020.010722

Abstract Laboratory experiments have been carried out to study the fluid flow in the wellbore of a horizontal gas well during the production process. The related pressure distribution has been determined considering different cases (different inflow media, different perforation opening methods and different liquid holdup). It has been found that the larger the fluid flow rate, the greater the pressure changes in the wellbore under the same hole opening mode. The uniformity of the perforation opening method was also an important factor affecting the magnitude of the wellbore pressure change. The liquid holdup also affected the pressure distribution, especially when the… More >

Lin Pan, Jinhong Xia, Hongxing Han^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1219-1228, 2020, DOI:10.32604/fdmp.2020.010545

Abstract In this paper, the discrete element method (DEM) is used to study the microstructure of expansive soils. The results of the numerical calculations are in agreement with the stress-strain triaxial test curve that is obtained for a representative expansive soil. Biaxial compression tests are conducted for different confining pressures (50 kpa, 100 kpa, and 150 kpa). Attention is paid to the following aspects: deviatoric stress, boundary energy, friction energy, bond energy, strain energy, kinetic energy, and the contact force between grains when the test specimen is strained and to the effect of the different confining pressures on the internal crack… More >

Yukun Lv, Jiaxi Yang, Jiawen Wang^*, Runcheng Zhang, Shuang Yang, Wentao Li

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1203-1217, 2020, DOI:10.32604/fdmp.2020.010489

Abstract Aiming at the problem that the total pressure loss of the flue of the electric precipitator of the 350 MW unit of a power plant to the inlet of the draft fan is too large, the numerical simulation software Fluent and the standard k-ε model was used to simulate the flue, the results show that the main part of the flue mean total pressure loss is derived from the confluence header and elbow. In order to reduce the loss and consider the cost of transformation, the concept of twodimensional feature surface is established, gradually proposed three sets of flue transformation… More >

Shaozhi Zhang, Ruoyi Xie, Mengjie Xu, Guangming Chen^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1177-1189, 2020, DOI:10.32604/fdmp.2020.010352

Abstract Pre-freezing is an important stage in freeze-drying processes. For the lyophilization of a cell, freezing not only plays a role for primary dehydration, but it also determines the amount of residual (intracellular or extracellular) water, which in turn can influence the solution properties and the choice of operation parameters. The freezing of human platelets in lyoprotectant solution is theoretically investigated here. A two-parameter model and an Arrhenius expression are used to describe cell membrane permeability and its temperature dependency. It is assumed that the intracellular solution is composed of four components: sodium chloride, trehalose, serum protein and water, while the… More >