Yuanjun Dai^1,2, Jingan Cui¹, Baohua Li^1,*, Cong Wang¹, Kunju Shi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.4, pp. 771-786, 2024, DOI:10.32604/fdmp.2023.029584

Abstract A numerical method has been used to analyze the flow field related to a NACA 0015 airfoil with and without a flap and assess the influence of the flap height and angle on the surface pressure coefficient, lift coefficient, and drag coefficient. The numerical results demonstrate that the flap can effectively improve the lift coefficient of the airfoil; however, at small attack angles, its influence is significantly reduced. When the angle of attack exceeds the critical stall angle and the flap height is 1.5% of the chord length, the influence of the flap becomes very evident. As the flap height… More >

Zhaolin Chen^1,*, Xiaohui Wei¹, Tianhang Xiao¹, Ning Qin²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09976

Abstract A computational study has been conducted on various airfoils to simulate flows at low Reynolds numbers 17,000 and 21,000 with Mach number changes from 0.25 to 0.85 to provide understanding and guidance for Mars rotory wing designs. The computational fluid dynamics tool used in this study is a Reynolds-averaged Navier–Stokes solver with a transition model (k-ω SST γ-Reθ). The airfoils investigated in this study include NACA airfoils (4, 5, and 6% camber), UltraThin airfoils, and thin cambered plates (3% camber, but various maximum camber locations). Airfoils were examined for lift and drag performance as well as surface pressure and flow… More >

Cho Mar Aye¹, Kittinan Wansaseub², Sumit Kumar³, Ghanshyam G. Tejani⁴, Sujin Bureerat¹, Ali R. Yildiz⁵, Nantiwat Pholdee^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.3, pp. 2111-2128, 2023, DOI:10.32604/cmes.2023.028632

Abstract This work presents multi-fidelity multi-objective infill-sampling surrogate-assisted optimization for airfoil shape optimization. The optimization problem is posed to maximize the lift and drag coefficient ratio subject to airfoil geometry constraints. Computational Fluid Dynamic (CFD) and XFoil tools are used for high and low-fidelity simulations of the airfoil to find the real objective function value. A special multi-objective sub-optimization problem is proposed for multiple points infill sampling exploration to improve the surrogate model constructed. To validate and further assess the proposed methods, a conventional surrogate-assisted optimization method and an infill sampling surrogate-assisted optimization criterion are applied with multi-fidelity simulation, while their… More > Graphic Abstract

Chunyan Zhang¹, Shuaishuai Wang^1,2, Yinhu Qiao^1,*, Zhiqiang Zhang^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2661-2679, 2023, DOI:10.32604/fdmp.2023.028059

Abstract Numerical simulations are conducted to improve the energy acquisition efficiency of H-type vertical axis wind turbines through the optimization of the related blade airfoil aerodynamic performance. The Bézier curve is initially used to fit the curve profile of a NACA2412 airfoil, and the moving asymptote algorithm is then exploited to optimize the design of the considered H-type vertical-axis wind-turbine blade airfoil for a certain attack angle. The results show that the maximum lift coefficient of the optimized airfoil is 8.33% higher than that of the original airfoil. The maximum lift-to-drag ratio of the optimized airfoil exceeds the maximum lift-to-drag ratio… More > Graphic Abstract

Yulin Tian^a , Chengyi Long^b, Linghong Tang^a,*

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-11, 2022, DOI:10.5098/hmt.19.18

Abstract In this study, the thermal-hydraulic performance of eight different printed circuit heat exchanger (PCHE) configurations with supercritical liquefied natural gas as the working fluid are studied by a numerical method. Firstly, the thermal-hydraulic performance of the PCHE with different airfoil fins are investigated at different operating pressures, which indicate that the PCHE with airfoil fins has better thermal performance but worse hydraulic performance when it operates at higher pressure condition. Furthermore, the effects of different airfoil configurations on the thermal-hydraulic performance are analyzed in detail. The results show that asymmetric airfoils can provide better heat transfer performance than symmetrical airfoils.… More >

Yuxing Yang, Peng Zhang^*, Meng Lv

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.6, pp. 1397-1409, 2023, DOI:10.32604/fdmp.2023.024916

Abstract The performances of turbine blades have a significant impact on the energy conversion efficiency of vertical solar power plants. In the present study, such a relationship is assessed by considering two kinds of airfoil blades, designed by using the Wilson theory. In particular, numerical simulations are conducted using the SST K − ω model and assuming a wind speed of 3–6 m/s and seven or eight blades. The two airfoils are the NACA63121 (with a larger chord length) and the AMES63212; It is shown that the torsion angle of the former is smaller, and its wind drag ratio is larger; furthermore,… More > Graphic Abstract

Xiyang Li¹, Yuhao Jia², Hui Zhang^1,*, Bin Cheng¹

Energy Engineering, Vol.119, No.6, pp. 2549-2567, 2022, DOI:10.32604/ee.2022.020854

Abstract Icing can significantly change the geometric parameters of wind turbine blades, which in turn, can reduce the aerodynamic characteristics of the airfoil. In-depth research is conducted in this study to identify the reasons for the decline of wind power equipment performance through the icing process. An accurate experimental test method is proposed in a natural environment that examines the growth and distribution of ice formation over the airfoil profile. The mathematical models of the airfoil chord length, camber, and thickness are established in order to investigate the variation of geometric airfoil parameters under different icing states. The results show that… More >

Shun He^1,*, Gaowei Cui²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.24, No.1, pp. 1-4, 2022, DOI:10.32604/icces.2022.08753

Abstract An investigation has been made into the nonlinear aeroelastic behavior of a supercritical airfoil (NLR 7301) considering free-play in transonic flow. Computational Fluid Dynamics (CFD) based on NavierStokes equations is implemented to calculate unsteady aerodynamic forces. A loosely coupled scheme with steady CFD and a graphic method are developed to obtain the static aeroelastic position. Frequency domain flutter solution with transonic aerodynamic influence coefficient is used to capture the linear flutter characteristic at different angle of attack (AoA). Time marching approach based on CFD is used to calculate the nonlinear aeroelastic response. The bifurcation diagram of pitching motion shows that… More >

Inamul Hasan^1,2,*, R. Mukesh², P. Radha Krishnan^1,2, R. Srinath¹, R. B. Dhanya Prakash²

Intelligent Automation & Soft Computing, Vol.33, No.1, pp. 567-584, 2022, DOI:10.32604/iasc.2022.023252

Abstract In this research, the aerodynamic performance and flow characteristics of NASA SC (2)-0714 airfoil and HH02 airfoil in the helicopter main rotor are evidently analyzed. The supercritical airfoil is used in the aircraft for attaining better transonic and high-speed flow characteristics. Moreover, a specialized helicopter airfoil called HH02 is used in the Apache helicopter rotor for increasing the operational speed. As most of the high-speed helicopters are using four-bladed main rotor configuration, it is analyzed with prior attention. The lift and thrust act in different directions for the forward phase of the flight whereas the lift and thrust act in… 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 >