Weibo Hu

State Key Laboratory of Aerodynamics

Stability in a Mach 4.5 boundary layer over backward-facing steps (BFSs) is investigated using numerical methods. Two types of cases are considered with different laminar inflow conditions, imposed with single-frequency or broadband-frequency modes, respectively. Compared with the typical K-type transition over a flat plate, the boundary layer tran...

The mixing mechanism of a transverse jet enhanced by high-frequency plasma energy de-position is investigated at Ma = 6.13 using both experimental measurements and improved delayed detached eddy simulation. The test configuration is a flat plate with Argon gas injected vertically at its center. The plasma actuator driven by 20 kHz and 50 kHz pulsed...

The flow over a forward-facing step (FFS) at 𝑀𝑎∞=1.7 and 𝑅𝑒𝛿=13718 is investigated by well-resolved large-eddy simulation. To investigate effects of upstream flow structures and turbulence on the low-frequency dynamics of the shock wave/boundary layer interaction (SWBLI), two cases are considered: one with a laminar inflow and one with a turbulent...

The control effects of a high-frequency pulsed discharge on a hypersonic separated flow induced by a 42{degree sign} compression ramp are studied with high-speed schlieren imaging. A discharge is generated between an electrode pair upstream of the ramp to introduce strong disturbances into the boundary layer. The discharge frequencies used are f d...

The effects of the incident angle of a freestream slow acoustic wave on the three-dimensional receptivity of a first mode are investigated in the case of a hypersonic boundary layer over a blunt cone. When the incident wave strikes the bow shock, the postshock slow acoustic wave on the leeward side of the incident wave is generated at an earlier lo...

The low-frequency unsteady behaviour of the flow over a forward-facing step (FFS) and backward-facing step (BFS) at Ma∞ = 1.7 and Re∞ = 1.3718 ×10^7m^−1 is investigated using a well-resolved large eddy simulation (LES). The mean and instantaneous flow field illustrate the unsteady features of the shock wave/boundary layer interaction (SWBLI) system...

The low-frequency unsteady motions behind a backward-facing step (BFS) in a turbulent flow at Ma=1.7 and Re∞=13.7×10^6 are investigated using a well-resolved large-eddy simulation. The instantaneous flow field illustrates the unsteady phenomena of the shock wave/boundary layer interaction (SWBLI) system, including vortex shedding in the shear layer...

The backward/forward-facing step (BFS/FFS) is one of the canonical geometries in aerospace engineering applications, the flow field over which has attracted extensive attention in the past decades. In a supersonic flow, laminar-to-turbulent transition and shock wave/boundary layer interaction (SWBLI) can occur over these configurations, which consi...

The low-frequency unsteady motions behind a backward-facing step (BFS) in a turbulent flow at Ma = 1.7 and Re∞ = 1.3718 × 10^5 is investigated using a well-resolved large-eddy simulation (LES). The instantaneous flow field illustrates the unsteady phenomena of the shock wave/boundary layer interaction (SWBLI) system, including vortex shedding in th...

The development of primary and secondary instabilities is investigated numerically for a supersonic transitional flow over a backward-facing step at Ma = 1.7 and Re=13 718. Oblique Tollmien–Schlichting (T–S) waves with properties according to linear stability theory (LST) are introduced at the domain inlet with zero, low, or high amplitude (cases Z...

The low-frequency unsteady motions behind a backward-facing step (BFS) in a turbulent flow at $Ma=1.7$ and $Re_\infty=1.3718\times 10^5$ is investigated using a well-resolved implicit large-eddy simulation (LES). The instantaneous flow field illustrates the unsteady phenomena of the shock wave/boundary layer interaction (SWBLI) system, including th...

Flow reconstruction from DMD mode $\phi_2$. The animation shows the contours of pressure gradient at 32 phase angles. The green solid and dashed lines indicate the mean reattachment shock and boundary layer edge. The while solid line is the instantaneous isoline of $u=0$. The black solid and dashed lines denote the instantaneous ioslines of $u^\pri...

Flow reconstruction from DMD mode $\phi_3$. The animation shows the contours of pressure gradient at 32 phase angles. The green solid and dashed lines indicate the mean reattachment shock and boundary layer edge. The while solid line is the instantaneous isoline of $u=0$. The black solid and dashed lines denote the instantaneous ioslines of $u^\pri...

Flow reconstruction from DMD mode $\phi_2$. The animation shows the contours of pressure gradient at 32 phase angles. The green solid and dashed lines indicate the mean reattachment shock and boundary layer edge. The while solid line is the instantaneous isoline of $u=0$. The black solid and dashed lines denote the instantaneous isolines of $u^\pri...

The transition mechanism and unsteady behavior behind a backward-facing step (BFS) in the supersonic regime at Ma=1.7 and Re_δ=13718 is investigated using large-eddy simulation (LES). The visualization of the flow field shows that the transition process behind the step is initiated by a Kelvin-Helmholtz (K-H) instability of the separated shearlayer...

The transition mechanism and unsteady behavior behind a backward-facing step (BFS) in the supersonic regime at Ma=1.7 and Re_δ=13718 is investigated using large-eddy simulation (LES). The visualization of the flow field shows that the transition process behind the step is initiated by a Kelvin-Helmholtz (K-H) instability of the separated shearlayer...

The path of laminar-to-turbulent transition behind a backward-facing step (BFS) in the supersonic regime at $Ma=1.7$ and $Re_{\delta_0}=13718$ is investigated using a very well-resolved large eddy simulation (LES). Five distinct stages are identified in the transition process by the visualisation of instantaneous flow. The transition is initiated b...

The unsteadiness of shock wave-boundary layer interactions is investigated in a transitional backward-facing step flow at $Ma=1.7$ and $Re_{\delta_0}=13718$ using large eddy simulation. The mean and instantaneous flow shows that the laminar inflow undergoes a laminar-to-turbulence transition in which Kelvin-Helmholtz vortices form, distort and even...