Results 251 to 260 of about 14,355 (292)

Micro-Ramps in Mach 5 Hypersonic Flow

50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2012
Shock/boundary layer interactions (SBLI) is an undesirable phenomenon occurring in high-speed propulsion system. The conventional method to overcome SBLI is using bleed system however a number of drawbacks are associated with it. This study investigates a novel type of flow control device called micro-ramps, a part of the micro vortex generators (VGs ...
Saad, M. R., Che Idris, A., Zare-Behtash, H., Kontis, K.   +3 more
openaire   +1 more source

Micro-Ramp Wake Structures Identified by Liutex

2021
Several vortex identification methods such as ∆, Q, λ2, λci, Ω criteria have been widely used to capture coherent structures in turbulent flows. Recently, a new vector named Liutex was proposed by Liu’s group to describe the local fluid rotation accurately.
Xiangrui Dong, Chaoqun Liu
openaire   +1 more source

Study on wake structure characteristics of a slotted micro-ramp with large-eddy simulation

Fluid Dynamics Research, 2017
Xiangrui Dong, Zhihua Chen, Gang Dong
exaly   +2 more sources

DECAY OF THE TURBULENT WAKE FROM THE SUPERSONIC MICRO RAMP

Proceeding of Eighth International Symposium on Turbulence and Shear Flow Phenomena, 2013
The wake resulting from two micro ramps operating in a supersonic boundary layer at Ma = 2:0 is investigated by means of PIV. Two micro ramps are investigated with height of 60% and 80% of the undisturbed boundary layer with thickness of 5.2 mm. The measurement domain encompasses the range from 10 to 32 ramp heights downstream of the device.
Sun, Z. (author), Van Oudheusden, B.W. (author), Schrijer, F.F.J. (author), Scarano, F. (author)   +3 more
openaire   +2 more sources

CFD Analysis of Micro-Ramps for Hypersonic Flows

Applied Mechanics and Materials, 2014
Air intake is a crucial component for supersonic and hypersonic air breathing propulsion devices. The intake must provide the required mass flow rate of air with minimal loss of stagnation pressure. A major difficulty in the stable operation of an intake is associated with shock wave boundary layer interaction (SBLI).
Ashish Mogrekar, Ramasami Sivakumar
openaire   +1 more source

Observations on the Mean and Turbulent Wake of a Micro-Ramp Array

45th AIAA Fluid Dynamics Conference, 2015
A preliminary study of a micro-ramp or micro vortex generator (MVG) array at Mach 1.6 and 2.2 shows that the wake appears to consist of those of individual MVG elements. Other than a small interference region near the vicinity of the MVG leading edges, the strong counter-rotating vortices shed by each MVG dominates the flowfield. These vortices isolate
Ezgihan Baydar, Frank K. Lu
openaire   +1 more source

Experimental Studies on Micro-ramps at Mach 5

2012
The performance of hypersonic propulsion can be critically affected by shock wave/boundary layer interactions (SBLIs), whose severe adverse pressure gradients can cause boundary layer separation. This phenomenon is very undesirable in engine intakes leading to total pressure loss and flow distortion which can cause engine unstart.
Erdem, Erinc, Kontis, Konstantinos, Yang, L, Saad, R   +3 more
openaire   +2 more sources

Boundary layer transition mechanisms behind a micro-ramp

Journal of Fluid Mechanics, 2016
The early stage of three-dimensional laminar-to-turbulent transition behind a micro-ramp is studied in the incompressible regime using tomographic particle image velocimetry. Experiments are conducted at supercritical micro-ramp height $h$ based Reynolds number $Re_{h}=1170$. The measurement domain encompasses 6 ramp widths spanwise and 73 ramp heights
Qingqing Ye, Ferry F. J. Schrijer, Fulvio Scarano   +2 more
openaire   +1 more source

Effect of micro-ramps on supersonic boundary layer past a double wedge

Journal of Visualization, 2017
The effect of micro-ramps on Mach 3 boundary layer structures past a double wedge was experimentally investigated in a supersonic low-noise wind tunnel using nano-tracer planar laser scattering (NPLS) technique. The fine structures of supersonic flow over the double wedge with and without the micro-ramps, as well as temporal and spatial evolutionary ...
Qinghu Zhang, Xiaobin Xu, Wang Xiong, Lin Jingzhou, Tong Hua   +4 more
openaire   +1 more source

Numerical investigations on the wake structures of micro-ramp and micro-vanes

Fluid Dynamics Research, 2013
Based on large eddy simulation, combined with the high-order WENO (weighted essentially non-oscillatory schemes) scheme, immersed boundary method and adaptive mesh refinement technique, the supersonic flow past a wall-mounted micro-ramp and two micro-vanes have been simulated. The different wake structures are presented and discussed.
Xue DaWen, Chen ZhiHua, Jiang XiaoHai, Fan BaoChun   +3 more
openaire   +1 more source