Huanhao Zhang

• Dr
• Nanjing University of Science and Technology

The jet can be applied to the yaw control of a projectile, however, the complex interaction of the jet with the supersonic mainstream makes the flow field complex and yaw force unpredictable. To reveal the evolution of flow structures under different pressure ratios (PRs), or momentum flux ratios, a transverse sonic jet injected into a supersonic l...

Based on ideal compressible magnetohydrodynamics (MHD) equations, the interface instability induced by the interaction between planar shock wave and the lightw gas (Helium) cylinder under the influence of the magnetic field with different directions was investigated numerically using the CTU(Corner Transport Upwind)+CT (Constrained Transport) algor...

With the shrink of critical dimensions of semiconductor devices to a few nanometers, atomic layer etching (ALE) has become an important technique to achieve single-atom resolution. ALE decouples plasma etching into two self-limiting reaction processes:passivation and etching processes, allowing for sequential removal of material atomic layer by lay...

To study the flow characteristics of the rapid mixing process of fuel and air in supersonic combustion chamber, this paper is based on the compressible Navier-Stokes equation, a sonic jet injected into a Mach 2.68 crossflow over a flat plate with a jet-to-crossflow pressure ratio of 36 is investigated numerically with the use of large eddy simulati...

In this paper，the Richtmyer—Meshkov instability is studied numerically by using the high resolution Roe scheme based on the two dimensional unsteady Euler equation，which is caused by the interaction between shock wave and the helium circular light gas cylinder with different component distributions．The numerical results are used to further discuss...

The Kelvin-Helmholtz instability (KHI) stems from the velocity shear in a single continuous fluid or a velocity difference across the interface between two distinct fluids. The effect of the transverse magnetic field on the KHI of the supersonic mixing layer is investigated by numerical method. An algorithm with corner-transport-upwind and constrai...

The Richtmyer–Meshkov instability (RMI) is caused by an incident planar shock wave impinging on the heavy-gas-density interface. We have numerically investigated the RMI controlled by different transverse magnetic-field strengths based on the ideal compressible magnetohydrodynamics (MHD) equations. The MHD equations are solved by the corner transpo...

In this paper, the Richtmyer-Meshkov instability has been studied numerically by using the high resolution Roe scheme based on the two-dimensional unsteady Euler equation, which was caused by the interaction between shock wave and the helium circular light gas cylinder with different component distributions. The numerical results further discuss th...

Based on the compressible Navier-Stokes equations combined with the fifth-order weighted essentially non-oscillatory scheme, this paper discusses the interaction of a planar shock wave with an annular SF 6 cylinder. The influence of the position and radius of inner cylinder on the evolution of the annular cylinder is examined in detail. Numerical s...

Based on Navier-Stokes equations, combined with fifth-order weighted essentially non-oscillatory scheme and adaptive structured grid refinement technique, interactions between converging shock and annular SF6 layers with different initial perturbation amplitudes and thickness are numerically investigated. The evolution mechanism of shock structures...

The evolution of the Kelvin-Helmholtz (KH) instability in the presence of classical hydrodynamics and magneto-hydro-dynamics is investigated numerically by using the magneto-hydro-dynamic (MHD) equations. The MHD equations are solved with the corner transport upwind plus constrained transport algorithm that guarantees the divergence-free constraint...

The Richtmyer-Meshkov instability (RMI) generated by the shock wave interacts with a density interface in the presence of a transverse magnetic field is investigated numerically using the ideal compressible Magneto-hydro-dynamic (MHD) equations. The MHD equations are solved with CTU+CT (Corner Transport Upwind + Constrained Transport) algorithm whi...

Based on the ideal magneto-hydro-dynamic equations (MHD) and adopting the CTU (Corner Transport Upwind) + CT (Constrained Transport) algorithm, the Richtmyer-Meshkov (RM) instability of the Gaussian distribution R22 gas column generated by the interaction of a planar shock wave with the gas column in the presence of magnetic field is investigated n...

Based on the compressible large eddy simulation method, combined with the hybrid scheme of the weighted essentially nonoscillatory scheme and the tuned central difference scheme, the interaction of the cylindrical converging shock wave with an equilateral triangle SF6 cylinder is numerically simulated in this work. The numerical results clearly sho...

The three-dimensional flow characteristics of the compressible vortex ring generated by under-expanded circular jets with two typical pressure ratios, i.e. $n=1.4$ (moderate) and 4.0 (high), are investigated numerically with the use of large-eddy simulations. Our results illustrate that these two pressure ratios correspond to different shock struct...

Based on magnetohydrodynamics(MHD), the evolution of the Richtmyer-Meshkov instability in different magnetic field configurations are studied. To ensure the zero magnetic divergence, an unsplit integration algorithm is adopted by combining corner transport upwind and constrained transport (CTU+CT) algorithm. The second order Godunov flux is obtaine...

One of the figures of the paper has been selected as the cover of the newest volume of JFM

The flow separation phenomenon often occurs in large area ratio nozzles of rocket engines, in order to study the relationship between the combustion chamber pressure and the flow separation point and the effect of flow separation on the nozzle. The numerical simulation of nozzle under different chamber pressures is carried out by using computationa...

Based on the large-eddy simulation, combined with the fifth-order weighted essentially non-oscillatory scheme and the two-order central difference scheme, the evolution of a square SF6 gas cylinder impacted by a converging shock wave has been numerically simulated. The numerical results present clearly the deformation of cylinder interface induced...

Sabot asymmetric discard after the projectile being launched from the muzzle at various angles of attack and 4Ma is investigated. This is implemented by the coupling computational fluid dynamics (CFD) and six degrees‐of‐freedom exterior ballistic code through the unstructured dynamic mesh and user defined function. The flow field characteristics du...

With the use of large eddy simulation (LES), the initial structure and mixing characteristics of both the subsonic and supersonic circular jets are studied, respectively. The stretched‐vortex model combined with the high‐order hybrid scheme is employed to solve the LES equations. The typical structures of the initial jet at different conditions hav...

Magnetohydrodynamic (MHD) equations are solved by using the CTU+CT (corner transport upwind + constrained transport) algorithm which guarantees the divergence-free constraint on the magnetic field. The interactions between shock wave and heavy or light triangular cylinder are investigated in detail in the cases with and without magnetic field. In t...

To ensure the safe separation process of a missile from internal weapons bay, the control device is mounted in front of the internal weapons bay to control the separation process. Based on the coupling of Navier-Stokes (N-S) equations and six-degrees-of-freedom (6DOF) rigid-body motion equations, the separation process of missile under four differe...

The Kelvin-Helmholtz instability of a parallel shear flow with a hyperbolic-tangent velocity profile has been simulated numerically at a high Reynolds number. The fluid is perfectly conducting with low viscosity, and the strength of the applied magnetic field varies from weak to strong. We found that the magnetic field parallel to the mainstream di...

Based on optimal Latin hypercube design for computer experiments, blind Kriging surrogate model and sequential quadratic programming method, the optimal design of the aerodynamic configuration of a 30mm tubular projectile is carried out with the use of commercial softwares, such as UG, ICEM CFD, FLUENT etc. The aerodynamic configuration has been op...

Based on large eddy simulation (LES), combined with high order hybrid schemes, the initial flow characteristics of the unsteady subsonic elliptic jet was investigated numerically. The numerical results illustrate the formation, variation and development of the subsonic elliptic jets’ initial flow structures. Moreover, the self-induced deformation o...

The governing equations of Large eddy simulation (LES) for compressible flow have been used to study the initial flow structure of supersonic underexpanded jet issuing from nozzle with square outlets. The numerical results indicate the main flow characters of compressible vortex loop, and the characteristic behavior of three-dimensional shock patte...

Richtmyer–Meshkov (RM) instability arises during the eruption of heavy gas cloud. In this study, we numerically study the effects of magnetic fields on the RM instability induced by the ionised cylindrical and spherical heavy gas cloud eruption using corner transport upwind + constrained transport algorithm. Our numerical results show that magnetic...

Based on Large-eddy simulation, combined with the high order hybrid schemes, the three-dimensional spatially-developing supersonic planar mixing layer at two density ratios s=1.0 and 0.138) were investigated numerically for Mac=1.1. The numerical results illustrate clearly the evolution of supersonic mixing layer under the effect of perturbation, a...

Based on the compressible Navier-Stokes equation, the initial flow structures of an iso-expanded subsonic square jet at Ma=0.6 was investigated numerically with the use of large eddy simulation (LES) and combination of the high-order hybrid WENO/TCD schemes. Numerical results illustrate clearly the formation and three-dimensional evolution of the p...

In order to investigate the flow separation control mechanism and the flow characteristics induced by vortex generator jet and shock/boundary layer interaction, based on the large eddy simulation method, combined with high order WENO/TCD hybrid scheme, the flow separation control by vortex generator jet has been simulated under the condition of Ma=...

Based on the compressible Navier-Stokes equation, the initial flow structures of a supersonic planar jet at Ma=1.4 were investigated numerically with use of large eddy simulation (LES) and combination of the high-order hybrid WENO/TCD schemes. The numerical results illustrate clearly the initial flow characteristics of a supersonic planar jet, such...

Based on Large-eddy simulation, combined with the high order hybrid schemes, the initial flow fields of moderately and highly underexpanded circular jets under two different nozzle pressure ratios (n) of 1.4 and 4.0 are investigated numerically, respectively. Our numerical results illustrated clearly the initial flow structures of two underexpanded...

The starting flow fields produced by a supersonic underexpanded planar jet are studied numerically with the use of large eddy simulation (LES). The three-dimensional (3D) structures and evolutions of the starting jet flows including compressible main vortex pair, vortex-induced shock waves, shock–vortex interactions and jet mixing have been illustr...

To reduce the drag of a normal hollow projectile, computational fluid dynamics (CFD) is applied to simulate numerically the flow fields of hollow projectiles with different shapes; the drag coefficients of different projectiles are calculated. The optimal geometry of hollow projectile with the minimum drag coefficient is obtained accordingly. Moreo...

The study of 3D flow structures of a lateral jet interacting with the supersonic mainstream is important for the flow separation control on the surface of supersonic aircrafts and fuel mixing of scramjet engines. The flow characteristics of the lateral jet on a flat under the condition of mainstream Mach number of Ma=4.0 is simulated with large-edd...

To discuss the main sources of aeroacoustic field and generation mechanism of acoustic waves, the process of initial flow field development in a subsonic pulse jet is simulated by using the large-eddy simulation and the high-order hybrid-weight essentially non-oscillatory scheme, and the corresponding aeroacoustic field is calculated directly based...

Numerical investigations of the projectile launch process with different muzzle brakes have been performed in a nearly realistic situation. Both two- and three-dimensional unsteady Euler equations are used as the governing equations. The hybrid Roe type scheme is employed to solve the flow fields with strong blast waves, and structured dynamic mesh...

To reveal the generating mechanism of the acoustic sources in a low convection Mach number planar mixing layer, in this paper, based on the high-order hybrid scheme, the spacial developed, planar mixing layer and its acoustic near field have been simulated. Our numerical results expose the phenomena of vortexlets generated by the instability of mix...

To reveal the generation mechanism of shocklet and its interaction process with the vortexes in a supersonic mixing layer. In this paper, the dynamics flow field of supersonic plane mixing layer has been simulated at a convective Mach number of Mc=0.65, based on the large-eddy simulation, combined with the high resolution 5th order hybrid TCD/WENO...

Based on LES (Large-eddy simulation), combined with the 5th-order hybrid TCD-WENO scheme, the initial flow field of an iso-expanded subsonic jet at Ma=0.6 was simulated numerically. The numerical results described the formation, variation and development process of the initial structures of the jet flow. Moreover, it is found that the vortex core i...

The processes of a high-speed projectile flying away from the bores through different muzzle brakes were numerically simulated by using the high resolution Roe scheme and the structured dynamic mesh techniques based on the two-dimensional unsteady Euler equation. The calculated results describe the evolution process of muzzle blast wave structures...

When shock waves passes through a triangle wedge (Schardin's problem), some complicated physical phenomena, including shock wave Mach refection and diffraction, wedge wake, vortexlet, etc. may occur. In this paper, the Schardin's problem is investigated numerically with the combination of the third-orderWENO scheme, structured adaptive mesh refinem...

Numerical simulations of a single ejector driven by one- and two-pulse detonation engines (PDE) were performed to investigate the thrust augmentation mechanism. The systems of conservative laws of inviscid fluid combined with the one-step chemical reaction model are discretized in Cartesian coordinates using the high resolution hybrid Roe/HLL schem...

Large eddy simulation (LES) has been used to simulate both non-reacting and reacting supersonic planar mixing layers at convective Mach number Mc=0.3. The different eddy characteristics of two cases have been visualized and discussed based on our calculated results, and the differences of mixing layer structures have also been shown, which can prov...

Numerical simulations of the complicated flow field of an unsteady supersonic ejector have been performed with the use of two-dimensional, homogeneous and reactive Euler equations, and the combination of the high resolution hybrid Roe/HLL scheme with AMR (Adaptive Mesh Refinement) technology. Simulation results described the processes of both the s...

Based on the one-step chemical reaction Euler equations, the high resolution hybrid Roe/HLL scheme and the adaptive mesh refinement (AMR) method were employed to numerically investigate the process of detonation induced by the collision of the diffracted shock waves inside a square tube with a cube mounted at the axis. And the effects of the tube b...

Based on two-dimensional Euler equations, and in combination with the high-resolution hybrid Roe/HLL (Harten-Lax-Van Leer) scheme and adaptive mesh refinement method, numerical simulations of single ejection driven by two pulse detonation engines (PDE) were performed. The results show the propagation processes of the ejection of the primary detonat...

The process of projectile flying away from a three-dimensional muzzle brake was numerically simulated using the three-dimensional unsteady Euler equations, the high resolution Roe scheme and the structured dynamic mesh techniques. Based on the calculated results, the main characteristics of the complicated three-dimensional transient effect of muzz...

Based on the one-step chemical reaction Euler equations, the high resolution hybrid Roe/HLL scheme and the AMR (Adaptive mesh refinement) method are employed to study the phenomenon of detonation induced by the collisions of the diffracted shock waves when the shock wave passes around double square obstacles in the tube filled with combustible gase...

Based on the Euler equation, the hybrid Roe/HLL scheme is employed to simulate the oblique detonation waves (ODWs). Furthermore, magnetohydrodynamic (MHD) control of both stable and unstable ODWs is investigated. It is shown that the stable ODW wave front can be controlled to the desired position under different inflow Mach numbers. However, for an...

Based on the homogenous fluid reaction N-S equations, the k-ε turbulent model and the EBU combustion model, the propagation of detonation wave in a sudden area change tube and the influences on the thrust performance of the main tube with different nozzles were investigated. Our results show that, a new detonation can be initiated promptly when the...