Xiaohui Cheng¹, Haiqing Si^1,*, Yao Li¹, Peihong Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.2, pp. 1729-1742, 2023, DOI:10.32604/cmes.2023.022694

Abstract To understand the influence of the initial release conditions on the separation characteristics of the store and improve it under high Mach number (Ma = 4) flight conditions, the overset grid method and the Realizable turbulence model coupled with an equation with six degrees of freedom are used to simulate the store released from the internal bay. The motion trajectory and the attitude angle of the store separation under the conditions of different centroid, velocity, height and control measures are given by the calculated result. Through analysis, the position of the centroid will affect the separation of the store, which needs to… More >

Abdul Aabid^1,*, Sher Afghan Khan², Muneer Baig¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.6, pp. 1877-1900, 2022, DOI:10.32604/fdmp.2022.021860

Abstract A method based on microjets is implemented to control the flow properties in a convergent-divergent nozzle undergoing a sudden expansion. Three different variants of this active control technique are explored numerically by means of a finite-volume method for compressible fluid flow: with the first one, the control is implemented at the base, with the second at the wall, while the third one may be regarded as a combination of these. When jets are over-expanded, the control is not very effective. However, when a favourable pressure gradient is established in the nozzle, the control becomes effective, leading to an increase in… 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 >

Dan Xie¹, Min Xu²

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.5, pp. 377-409, 2013, DOI:10.3970/cmes.2013.093.377

Abstract We apply a simple proper orthogonal decomposition (POD) method to compute the nonlinear oscillations of a degenerate two-dimensional fluttering plate undergoing supersonic flow. First, the von Karman’s large deflection theory and quasi-steady aerodynamic theory are employed in constructing the governing equations of the simply supported plate. Then, the governing equations are solved by both the Galerkin method and the POD method. The Galerkin method is accurate but sometimes computationally expensive, since the number of degrees of freedom (dofs) required is relatively large provided that nonlinearity is strong. The POD method can be used to capture the complex dynamics of a… More >

Roland Martin¹, Carlos Couder-Castaneda¹

CMES-Computer Modeling in Engineering & Sciences, Vol.63, No.1, pp. 47-78, 2010, DOI:10.3970/cmes.2010.063.047

Abstract We develop an unsplit convolutional perfectly matched layer (CPML) technique to absorb efficiently compressible viscous flows and their related supersonic or subsonic regimes at the outer boundary of a distorted computational domain. More particularly subsonic outgoing flows or subsonic wall-boundary layers close to the PML are well absorbed, which is difficult to obtain without creating numerical instabilities over long time periods. This new PML (CPML) introduces the calculation of auxiliary memory variables at each time step and allows an unsplit formulation of the PML. Damping functions involving a high shift in the frequency domain allow a much better absorption of… More >

M. Dandani^1,*, V. Lepiller², A. Ghezal³, P. Desevaux⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.14, No.1, pp. 23-37, 2018, DOI:10.3970/fdmp.2018.014.023

Abstract The present study deals with the numerical visualization of the mixing process in a 2D supersonic ejector. The mixing process is visualized using two CFD flow visualization methods. The first method consists in introducing discrete particles in the secondary flow and computing their trajectories. The second method consists in modeling the diffusion of a passive scalar introduced in one of the two flows. The mixing process is investigated in the case of a conventional 2D supersonic ejector and a second case of an ejector equipped with transverse micro jets. Flow visualizations obtained show the existence of a significant mixing enhancement… More >