Investigation on Turbulent Expansion-Corner Flow With Shock Impingement

Chung, Kung Ming

doi:10.1115/1.1343084

Cited by 8 publications

(5 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The wall static pressure showed overshoot compared with inviscid pressure levels and the suppression of SWBLI was experimentally confirmed when the shock impinging point was located downstream of the expansion corner. Chung (2001) investigated a transonic case in which the Mach number was 1.28 and the incident shock impinged exactly at the expansion corner. Wall static pressure measurements for different shock intensities (wedge angles of 1, 3 and 5) and expansion corners (5, 10 and 15) reveal that the downstream peak pressure fluctuation depends on the coupling of the impinging shock and expansion waves.…”

Section: Introductionmentioning

confidence: 99%

On incident shock wave/boundary layer interactions under the influence of expansion corner

Guo,

Tan,

Zhang

et al. 2024

J. Fluid Mech.

View full text Add to dashboard Cite

Cowl-induced incident shock wave/boundary layer interactions (ISWBLIs) under the influence of shoulder expansion represent one of the dominant phenomena in supersonic inlets. To provide a more comprehensive understanding of how an expansion corner affects the ISWBLI, a detailed experimental and analytical study is performed in a Mach 2.73 flow in this work. Pressure measurement, schlieren photography and surface oil-flow visualisation are used to record flow features, including the pressure distribution, separation extent and surface-flow topological structures. Our results reveal three types of ISWBLIs influenced by the expansion corner. When the shock intensity is weak, the separation is small scale with the expansion waves emanating from the expansion corner. This is the first type of expansion-corner-affected ISWBLI (EC-ISWBLI). When the incident shock wave is strong, large-scale separation occurs, accompanied by the disappearance of expansion waves, forming the second type of EC-SWBLI. The expansion corner induces a ‘lock-in’ effect in which the separation onset is consistently locked near the expansion corner regardless of the incident shock intensity and impingement position. The third type of EC-ISWBLI occurs when the shock is sufficiently strong and the impingement point is close to the expansion corner. In this interaction, the ‘lock-in’ effect ceases to manifest. Moreover, a shock polar-incorporating inviscid model is employed to elucidate the shock patterns. Two criteria are established by combining free interaction theory with this model. The first criterion provides valuable insights into the evolution of separations with a minimal overall pressure rise and the second criterion determines the threshold for the occurrence of the ‘lock-in’ effect.

show abstract

Section: Introductionmentioning

confidence: 99%

On incident shock wave/boundary layer interactions under the influence of expansion corner

Guo,

Tan,

Zhang

et al. 2024

J. Fluid Mech.

View full text Add to dashboard Cite

show abstract

“…They reported a reduction in bubble size when its edge is closely located to the corner. Similarly, the effects of expansion corners in the vicinity of SWBLI were considered by few researchers 9–11 . Quan et al 12 experimentally investigated the benefits of installing herringbone riblets at the leading edge of a double wedge structure subjected to Mach 5 flow.…”

Section: Introductionmentioning

confidence: 99%

“…Similarly, the effects of expansion corners in the vicinity of SWBLI were considered by few researchers. [9][10][11] Quan et al 12 experimentally investigated the benefits of installing herringbone riblets at the leading edge of a double wedge structure subjected to Mach 5 flow. They reported that the expansion waves generated due to the presence of riblets weaken the leading edge shock resulting in less separation.…”

mentioning

confidence: 99%

“…From the literature reported findings, it is noticed that the presence of an expansion fan significantly affects various flow phenomena, such as its presence in the vicinity of an SWBLI can lead to lower flow separation. 3,4,[6][7][8][9][10][11] Furthermore, the presence of an expansion fan can delay the occurrence of Mach reflection, 5,16,17 can diminish the shock strength passing through ducts, 18,19 and decrease the overpressure region created by a high-speed train entering a tunnel, 15 and can lead to high drag in SCB. 22,23 It is observed that the majority of the studies are limited to airflow medium in the lower enthalpy range where perfect gas assumptions are true.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Shock/expansion fan interaction with real gas effects for Earth and Mars atmospheric conditions

2022

View full text Add to dashboard Cite

Numerical simulations are performed to investigate the real gas effects on shock/expansion fan interaction. Initial perfect gas simulations at low enthalpy capture the flow structures efficiently and outcomes are found to have excellent agreement with the analytical calculations. Furthermore, the simulations with the real gas solver for different enthalpies showed that the variation in enthalpy significantly changes the flow structures. It is observed that an increase in enthalpy leads to a decrease and increase in the postshock and postexpansion fan Mach numbers, respectively. Another important observation is the decrement in the peak pressure ratio with an increment in the enthalpy. These effects are noted to be more pronounced for Mars's environment due to the higher dependency of specific heat on temperature.computational fluid dynamics, Earth and Martian atmospheric simulations, expansion fan, hypersonic flow, real gas flow, shock waves | INTRODUCTIONThe design of high-speed 1,2 aircraft necessitates the appropriate predictions of flow structures associated with it. These flights often encounter shocks and expansion fans. Furthermore, these shock waves and expansion fans may interact with each other. The presence of shock/ expansion fan interaction may complicate the flow structures by affecting the boundary-layer

show abstract

“…Computational study of these complex flow-structures is often done using the Reynolds Averaged Navier Stokes (RANS) simulations, owing to its low computation cost [1,2]. Several studies have been conducted to investigate parameters like surface pressure rise, effect of wall temperature [3] in SBLIs with varying conditions and configurations [4,5]. Among these, predictions for SBLIs with strong shock waves have been found unsatisfactory, especially for eddy viscosity based models.…”

mentioning

confidence: 99%

A Phenomenological Model for Turbulent Heat Flux in High-Speed Flows With Shock-Induced Flow Separation

Pathak

Roy

Sinha

2018

Journal of Fluids Engineering

View full text Add to dashboard Cite

High-speed flows with shock waves impinging on turbulent boundary layers pose severe challenge to current computational methods and models. Specifically, the peak wall heat flux is grossly overpredicted by Reynolds-averaged Navier–Stokes (RANS) simulations using conventional turbulence models. This is because of the constant Prandtl number assumption, which fails in the presence of strong adverse pressure gradient (APG) of the shock waves. Experimental data suggest a reduction of the turbulent Prandtl number in boundary layers subjected to APG. We use a phenomenological approach to develop an algebraic model based on the available data and cast it in a form that can be used in high-speed flows with shock-induced flow separation. The shock-unsteadiness (SU) k–ω model is used as the baseline, since it gives good prediction of flow separation and the regions of APG. The new model gives marked improvement in the peak heat flux prediction near the reattachment point. The formulation is applicable to both attached and separated flows. Additionally, the simplicity of the formulation makes it easily implementable in existing numerical codes.

show abstract

Investigation on Turbulent Expansion-Corner Flow With Shock Impingement

Cited by 8 publications

References 23 publications

On incident shock wave/boundary layer interactions under the influence of expansion corner

On incident shock wave/boundary layer interactions under the influence of expansion corner

Shock/expansion fan interaction with real gas effects for Earth and Mars atmospheric conditions

A Phenomenological Model for Turbulent Heat Flux in High-Speed Flows With Shock-Induced Flow Separation

Contact Info

Product

Resources

About