Effects of subcavity in supersonic cavity flow

Panigrahi, C.; Vaidyanathan, Aravind; Nair, Manoj T.

doi:10.1063/1.5079707

Cited by 38 publications

(13 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…And this minimum pressure can result in positive or negative pressure as Mach number changes, which result positive or negative coefficient of pressure (C p ) at different location of the cavity. Negative pressure coefficient distribution across the cavity can result in decrease in drag [21].…”

Section: Open Cavitymentioning

confidence: 99%

Numerical Investigation of Supersonic Turbulent Flow Over Open Cavities

Sah¹,

Ghosh²

2021

IJFMTS

View full text Add to dashboard Cite

The study of cavity flow is one of the most important research topics of unsteady aerodynamics. Supersonic turbulent flows over a cavity are mostly encountered in missiles, turbomachinery, and high-speed aircraft. The turbulence inside the cavity gives rise to excess drag, acoustic waves, pressure fluctuations, and vibrations which may lead to numerous problems like excess fuel consumption, failure of missile trajectory or mechanical parts, and aerodynamic heating. We conduct numerical simulations to investigate the flow and compare our results to existing experimental data to show quantitative validation. We then investigate the effect of the Mach number of the turbulent supersonic flow on the pressure contours and the vortical structures inside the cavity and the subsequent effect on other flow parameters like acoustic waves. Thereafter, we propose two modifications of the cavity geometry, a) slanted edges and b) smoothened corners with slanted edges, to improve the aerodynamic performance. ANSYS ICEM tool has been used for the fine mesh generation of our cavity geometry and all the simulation was run on ANSYS fluent software. The K-ω SST turbulence model was used for the simulation as it can capture the near-wall property with reasonable accuracy and a grid independence study was carried out to find the correct solution of the Navier-Stokes equation was proceeding by the solver. The parameters like pressure contours, streamline pattern, coefficient of pressure distribution and sound pressure level (SPL) has been found and compared for both modified and unmodified open cavity at different Mach number. The modifications suggested show a significant improvement over the open cavity designs in the mean pressure distribution and sound pressure level distributions.

show abstract

Section: Open Cavitymentioning

confidence: 99%

Numerical Investigation of Supersonic Turbulent Flow Over Open Cavities

Sah¹,

Ghosh²

2021

IJFMTS

View full text Add to dashboard Cite

show abstract

“…Measurements are taken at different locations. Unsteady statistics are collected in particular at three probing locations along the cavity wall ([s/D] = 0.25, 2, 3.75), which are later utilized to understand the flow physics and also to compare with the findings of Panigrahi et al 20 . Two streamwise rakes extending between −1 ≤ [x/D] ≤ 3 are placed at differed transverse locations ([y/D] =0, and 0.5) in the freestream to understand the influence of cavity dynamics on the shock oscillations.…”

Section: A Geometrical Configurationmentioning

confidence: 99%

“…Confined supersonic stream is encountered in variety of gas-dynamic scenarios including flow through ducts [1][2][3][4] , overexpanded nozzles [5][6][7] , isolator of scram-jet inlets [8][9][10][11] , enclosed open jet wind-tunnels [12][13][14] , and ejectors [15][16][17][18] , where the influence of nearby walls on the quality of flow is substantial. One among such a flow field is supersonic flow past a confined cavity [19][20][21][22] . Mixed-compression inlet for shock-wave boundary layer control 23,24 , resonator type supersonic nozzles 25,26 , gas-dynamic lasers 27,28 , and scram-jet combustors 29,30 often employ cavities in supersonic flow which are placed in closed proximity to the surrounding walls.…”

Section: Introductionmentioning

confidence: 99%

Shock and shear layer interaction in a confined supersonic cavity flow

Karthick

2021

Preprint

View full text Add to dashboard Cite

The impinging shock of varying strengths on the free shear layer in a confined supersonic cavity flow is studied numerically using the detached-eddy simulation. The resulting spatiotemporal variations are analyzed between the different cases using unsteady statistics, x − t diagrams, spectral analysis, and modal decomposition. A confined passage height of H/D = 2 and a cavity of length to depth ratio L/D = 2 at a freestream Mach number of M ∞ = 1.71 is considered. Impinging shock strength is controlled by changing the ramp angle (θ ) on the top-wall. The static pressure change across the impinging shock (p 2 /p 1 ) is used to quantify the shock strength. Five different cases are realized: [p 2 /p 1 ] = 1.0, 1.2, 1.5, 1.7 and 2.0. At [p 2 /p 1 ] = 1.5, fundamental fluidic mode or Rossiter's frequency corresponding to n = 1 mode vanishes whereas frequencies correspond to higher modes (n = 2 and 4) resonate. Wavefronts interaction from the longitudinal reflections inside the cavity with the transverse disturbances from the shock-shear layer interactions is identified to drive the strong resonant behavior. Due to Mach-reflections inside the confined passage at [p 2 /p 1 ] = 2.0, shock-cavity resonance is lost. Besides, the cavity wall experiences a higher pressure of 25% for [p 2 /p 1 ] = 1.0 due to shock loading. Based on the present findings, an idea to use a shock-laden confined cavity flow in an enclosed supersonic wall-jet configuration as passive flow control or a fluidic device is also demonstrated.

show abstract

“…Further studies [17][18][19] showed that using a cavity after the injector significantly improves the combustion efficiency in a supersonic flow. The effect of sub-cavity in a supersonic cavity flow was studied by Panigrahi et al [20], who noted that the sub-cavity mitigates the shear layer reattachment at the aft wall of the cavity.…”

Section: Introductionmentioning

confidence: 99%

The Implication of Injection Locations in an Axisymmetric Cavity-Based Scramjet Combustor

2021

View full text Add to dashboard Cite

This paper presents the effect of cavity-based injection in an axisymmetric supersonic combustor using numerical investigation. An axisymmetric cavity-based angled and transverse injections in a circular scramjet combustor are studied. A three-dimensional Reynolds-averaged Navier–Stokes (RANS) equation along with the k-ω shear-stress transport (SST) turbulence model and species transport equations are considered for the reacting flow studies. The numerical results of the non-reacting flow studies are validated with the available experimental data and are in good agreement with it. The performance of the injection system is analyzed based on the parameters like wall pressures, combustion efficiency, and total pressure loss of the scramjet combustor. The transverse injection upstream of the cavity and at the bottom wall of the cavity in a supersonic flow field creates a strong shock train in the cavity region that enhances complete combustion of hydrogen-air in the cavity region compared to the cavity fore wall injection schemes. Eventually, the shock train in the flow field enhances the total pressure loss across the combustor. However, a marginal variation in the total pressure loss is observed between the injection schemes.

show abstract

Effects of subcavity in supersonic cavity flow

Cited by 38 publications

References 21 publications

Numerical Investigation of Supersonic Turbulent Flow Over Open Cavities

Numerical Investigation of Supersonic Turbulent Flow Over Open Cavities

Shock and shear layer interaction in a confined supersonic cavity flow

The Implication of Injection Locations in an Axisymmetric Cavity-Based Scramjet Combustor

Contact Info

Product

Resources

About