Hao Cheng, Guangsheng Du^*, Meng Zhang, Kun Wang, Wenbin Bai

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.4, pp. 685-698, 2020, DOI:10.32604/fdmp.2020.09673

Abstract The determination of the circulation for wind turbine blades is an important problem in engineering. In the present study, we develop a specific approach to evaluate the integral that represents mathematically the circulation. First the potentialities of the method are assessed using a two-dimensional NACA64_A17 airfoil as a testbed and evaluating the influence of different integration paths and angles of attack on the circulation value. Then the method is applied to blades with different relative heights in order to provide useful reference data to be used for the optimization and reverse design of wind turbine blades. As shown by the… More >

Bin Wang¹, Jing Zheng¹, Yuanyuan Yu^1,2, Runmin Lv¹, Changyue Xu^1,*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.4, pp. 675-684, 2020, DOI:10.32604/fdmp.2020.09681

Abstract Rocket sleds belong to a category of large-scale test platforms running on the ground. The applications can be found in many fields, such as aerospace engineering, conventional weapons, and civil high-tech products. In the present work, shock-wave/rail-fasteners interaction is investigated numerically when the rocket sled is in supersonic flow conditions. Two typical rocket sled models are considered, i.e., an anti-D shaped version of the rocket sled and an axisymmetric slender-body variant. The dynamics for Mach number 2 have been simulated in the framework of a dynamic mesh method. The emerging shock waves can be categorized as head-shock, tailing-shock and reflected-shock.… More >

Bin Zhang^*, Yongzhen Wang, Jiaqing Zheng, Dan Liu

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 665-674, 2020, DOI:10.32604/fdmp.2020.09314

Abstract The relationship among the working temperature, pressure and current density of a Solid oxide fuel cell (SOFC) and its output power and efficiency are analyzed in the framework of a theoretical model able to provide, among other things, the volt ampere characteristic curve. In particular, following the principle of temperature matching and cascade utilization, we consider a gas turbine (GT) and a LiBr absorption chiller to recycle the high-grade exhaust heat produced by the considered SOFC. This distributed total energy system is set up with the intent to meet typical needs of buildings for cooling, heating and power (CCHP). The… More >

Shengyang Feng^1,2,3,*, Dongbo Xiong⁴, Guojie Chen⁵, Yu Cui¹, Puxin Chen¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 651-663, 2020, DOI:10.32604/fdmp.2020.07981

Abstract Convection and diffusion are the main factors affecting radon migration. In this paper, a coupled diffusion-convection radon migration model is presented taking into account turbulence effects. In particular, the migration of radon is simulated in the framework of the k-ε turbulence model. The model equations are solved in a complex 3D domain by the finite element method (FEM). Special attention is paid to the case study about radon migration in an abandoned air defense shelter (AADS). The results show that air convection in a confined space has a great influence on the radon migration and the radon concentration is inversely… More >

Yongkang Zheng^1,2,*, Chao Yan¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 637-650, 2020, DOI:10.32604/fdmp.2020.09694

Abstract The flow field inside the combustor of a scramjet is highly complicated and the related turbulent Prandtl and Schmidt numbers have a significant impact on the effective numerical prediction of such dynamics. As in many cases researchers set these parameters on the basis of purely empirical laws, assessing their impact (via parametric numerical simulations) is a subject of great importance. In the present work, in particular, two test cases with different characteristics are selected for further evaluation of the role played by these non-dimensional numbers: Burrows-Kurkov case and DLR case. The numerical results indicate that these parameters influence ignition location.… More >

Qingyun Yan¹, You Li², Yuanhong Zhu³, Kui Cheng³, Xueli Huang³, Cong Qi³, Xuemin Ye^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 623-636, 2020, DOI:10.32604/fdmp.2020.09669

Abstract A hot primary-air pipe system is the bridge connecting an air-preheater with a coal mill in power generation stations. The effective geometrical configuration of the pipe network greatly affects the air flow distribution and consequently influences the safe and economic operation of milling systems in power stations. In order to improve the properties of the air flow, in the present work the SIMPLEC method is used to simulate numerically the flow field for the original layout of the system. As a result, the internal mechanisms influencing the uneven pressure drop in each branch are explored and three optimization schemes are… More >

Jiyuan Zhang¹, Linbo Wang¹, Chengqiang Zhang¹, Shuzhan Bai^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 615-621, 2020, DOI:10.32604/fdmp.2020.09654

Abstract The influences of steam and sulfide on the efficiency of NOx reduction using ammonia (NH₃) over the nanometer-class V-W/Ti catalyst in conditions of high temperature is experimentally investigated using a steady-flow reactor. The results showed that selective catalytic reduction (SCR) is inhibited by H₂O at low temperature, but higher NO conversion efficiency is achieved at high temperature since the reaction of NH3 oxidized by O₂ to NOx is inhibited by H₂O. The activity of SCR is promoted by SO₂ in the temperature range of 200~500° C, the NO conversion efficiency was improved to 98% from 94% by adding SO₂. SCR… More >

Jingying Wang, Fangzhou Han^*, Li Lei, Chunhian Lee

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 601-613, 2020, DOI:10.32604/fdmp.2020.09624

Abstract Accurate aerodynamic heating prediction is of great significance to current manned space flight and deep space exploration missions. The temperature in the shock layer surrounding the reentry vehicle can reach up to 10,000 K and result in remarkable thermochemical nonequilibrium, as well as considerable radiative heat transfer. In general, high-temperature flow simulations coupled with thermal radiation require appropriate numerical schemes and physical models. In this paper, the equations governing hypersonic nonequilibrium flow, based on a three-temperature model combined with a thermal radiation solving approach, are used to investigate the radiation effects in the reentry shock layer. An axisymmetric spherical case… More >

Lin Wang¹, Chunguo An², Nini Wang², Yaming Ping¹, Kun Wang¹, Ming Gao^1,*, Suoying He¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 585-600, 2020, DOI:10.32604/fdmp.2020.09611

Abstract Numerical simulation are conducted to explore the characteristics of the axial inflow and related aerodynamic noise for a large-scale adjustable fan with the installation angle changing from −12° to 12°. In such a range the maximum static (gauge) pressure at the inlet changes from −2280 Pa to 382 Pa, and the minimum static pressure decreases from −3389 Pa to −8000 Pa. As for the axial intermediate flow surface, one low pressure zone is located at the junction of the suction surface and the hub, another is located at the suction surface close to the casing position. At the outlet boundary,… More >

Ke Sun, Da Li, Hao Liu, Shuzhan Bai^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 573-584, 2020, DOI:10.32604/fdmp.2020.09591

Abstract In order to effectively implement DPF (Diesel Particulate Filters) regeneration control, thermal management of exhaust products before and inside Diesel Oxidation Catalyst (DOC) is necessary. In the present study, the Influence of the intake throttle valve and late post injection process on temperature rise inside DOC is analyzed through engine bench tests. The steady experiment results show that adjustment of the intake throttle valve can effectively increase exhaust temperature before DOC; in particular, with intake throttle valve opening at 20%, temperature before DOC can be increased by about 170°C with respect to the full opening. An increase in the late… More >