Cheng-Yeh Li, Jui-Hsiang Kao^*

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.3, pp. 2277-2304, 2024, DOI:10.32604/cmes.2023.030215

Abstract The performance of a water jet propulsion system is related to the inlet duct, rotor, stator, and nozzle. Generally, the flow inlet design must fit the bottom line of the hull, and the design of the inlet duct is often limited by stern space. The entire section, from the rotor to the nozzle through the stator, must be designed based on system integration in that the individual performance of these three components will influence each other. Particularly, the section from the rotor to the nozzle significantly impacts the performance of a water jet propulsion system. This study focused on nozzle… More >

Zhigang Wang, Bin Zheng, Peidong Zhao, Baoli Wang, Fanyan Meng, Wenke Xu, Jian Meng^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.2, pp. 365-382, 2024, DOI:10.32604/fdmp.2023.030302

Abstract Heavy-fuel engines are widely used in UAVs (Unmanned Autonomous Vehicles) because of their reliability and high-power density. In this study, a combustion model for an in-cylinder direct injection engine has been implemented using the AVL FIRE software. The effects of the angle of nozzle inclination on fuel evaporation, mixture distribution, and combustion in the engine cylinder have been systematically studied at 5500 r/min and considering full load cruise conditions. According to the results, as the angle of nozzle inclination increases, the maximum combustion explosion pressure in the cylinder first increases and then it decreases. When the angle of nozzle inclination… More > Graphic Abstract

Jiefeng Wang¹, Eddie Yin Kwee Ng^2,*, Jianwu Li¹, Yanhao Cao¹, Yanan Huang¹, Liang Li^1,2,3,*

Frontiers in Heat and Mass Transfer, Vol.21, pp. 1-31, 2023, DOI:10.32604/fhmt.2023.045510

Abstract The flow structure of the vortex cooling is asymmetrical compared to the traditional gas turbine leading edge cooling, such as the impingement cooling and the axial flow cooling. This asymmetrical property will affect the cooling performance in the blade leading edge, whereas such effects are not found in most of the studies on vortex cooling due to the neglect of the mainstream flow in the airfoil channel. This study involves the mainstream flow field and the rotational effects based on the profile of the GE E³ blade to reveal the mechanism of the asymmetrical flow structure effects. The nozzle position… More > Graphic Abstract

Xin Li¹, Shaohan Zheng^1,2, Yuliang Zhang^1,*, Minfeng Lv³

Frontiers in Heat and Mass Transfer, Vol.21, pp. 245-264, 2023, DOI:10.32604/fhmt.2023.041778

Abstract This article aims to reveal the transient thermal characteristics of the solid domain in a nozzle flowmeter when measuring fluids of varying temperatures. Based on finite element method, the transient numerical calculation of the thermal characteristics of each component of the nozzle flowmeter has been conducted. The research shows that: as the fluid passes through the flowmeter, the high heat flux area inside the nozzle flowmeter gradually transfer from the center of the nozzle to the inlet and outlet, as well as the pressure tapping points upstream and downstream; High thermal stress zones are present near the upstream and downstream… More >

Seyed Ehsan Rafiee^*, M. M. Sadeghiazad

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-15, 2016, DOI:10.5098/hmt.7.13

Abstract The aim of this investigation is study on separation phenomenon inside a special vortex tube affected by structural and physical factors including; throttle diameter, nozzle number and injection pressure as well as the parametric optimization based on separation efficiency using experimental and 3D-CFD methods. The results show that convergent VT with Dth=5.5mm provides 30.01% and 20.04% higher cooling and heating effectiveness compared to basic model. As another result, the higher injection pressure, the higher cooling effectiveness. The cooling effectiveness improves (16.86%) with increase in slot number up to N=4, then decreases. The maximum disagreement between experimental and predicted values is… More >

Yu Gao¹, Zhenqiang Xu^2,3,*, Kaixiang Shen^2,3,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.1, pp. 179-192, 2024, DOI:10.32604/fdmp.2023.030499

Abstract Hydraulic jetting is a form of fracturing that involves using a high-pressure jet of water to create fractures in the reservoir rock with a nozzle serving as the central component of the hydraulic sandblasting perforation tool. In this study, the flow behavior of the nozzle is simulated numerically in the framework of a SST k-ω turbulence model. The results show that the nozzle structure can significantly influence the jet performance and related cavitation effect. Through orthogonal experiments, the nozzle geometric parameters are optimized, and the following configuration is found accordingly: contraction angle 20°, contraction segment length 6 mm, cylindrical segment… More >

Jingjing Gao, Xingkai Zhang^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.1, pp. 109-127, 2024, DOI:10.32604/fdmp.2023.030106

Abstract A new approach and a new related distribution system are proposed to address the issue of uneven steam injection caused by the different suction capacities of the used wells during the application of steam “stimulation” methods for enhanced oil recovery. The new distribution system consists of a swirler, spiral dividing baffles, and critical flow nozzles. Numerical simulations are used to analyze the flow-field and degree of steam homogeneity obtained with such an approach. The results indicate that a higher inlet pressure leads to better results. Additionally, the internal flow field becomes more stable, and the deviation from an even distribution… More >

Zhongshuai Chen^1,2, Hongjian Ni^1,*, Xueliang Pei², Yu Gao³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.12, pp. 2953-2963, 2023, DOI:10.32604/fdmp.2023.029491

Abstract The actuator is a key component of the creaming tool in drilling applications. Its jet performances determine the effective reaming efficiency. In this work, a new selective reaming tool is proposed and the RNG k-ε turbulence model is used to calculate its internal and external flow fields. In particular, special attention is paid to the design of the flushing nozzle. The results show that the jet originating from the flushing nozzle has a significant influence on rock cutting and blade cooling effects. In turn, the jet performances depend on geometric structure of the creaming actuator. In this framework, a conical-cylindrical… More >

Yaofei Zhang¹, Guoxiang Li¹, Shuzhan Bai¹, Ke Sun^1,*, Guihua Wang^1,*, Yujie Jia², Zhengxian Fang²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.11, pp. 2933-2951, 2023, DOI:10.32604/fdmp.2023.028804

Abstract Multiphase simulations based on the VOF (Volume of Fluid) approach, used in synergy with the cavitation Schnerr-Sauer method and the K-Epsilon turbulence model, have been conducted to study the behavior of an injector nozzle as a function of relevant structural parameters (such as the spray hole diameter and length). The related performances have been optimized in the framework of orthogonal experimental design and range analysis methods. As made evident by the results, as the spray hole diameter increases from 0.10 to 0.20 mm, the outlet mass flow rate grows by 243.23%. A small diameter of the spray hole, however, has… More >

Rongge Xiao^a , Wenbo Jin^a,*, Shicong Han^b , Rui Li^a , Xuewen Cao^c

Frontiers in Heat and Mass Transfer, Vol.9, pp. 1-8, 2017, DOI:10.5098/hmt.9.6

Abstract Combines theories of gas dynamics, fluid dynamics and numerical heat transfer theory, the condensing flow characteristics of water vapor in wet natural gas within the Laval nozzle were studied. A mathematical model was developed to predict the spontaneous condensing phenomenon in the supersonic flows using the classical nucleation and droplet growth theories. The numerical approach is validated with the experimental data by using UDF and UDS modules in FLUENT software, which shows a good agreement between them, and showed that the mathematical model can better predict the parameter changes in the condensation process. The condensation characteristics of water vapor in… More >