@article{khan_madabushi_ghosh_edwards_narayanaswamy_2024, title={Numerical investigations of shock/boundary-layer interaction and control for Mach 2.5 flow in an axisymmetric inlet}, volume={154}, ISSN={["1626-3219"]}, url={https://doi.org/10.1016/j.ast.2024.109468}, DOI={10.1016/j.ast.2024.109468}, abstractNote={The present work investigates the application of vortex generators for separation control in axisymmetric isolator flows. Reynolds-Averaged Navier-Stokes computations were performed to simulate a Mach 2.5 flow past a half-isolator geometry with a 20∘ axisymmteric compression ramp based on the experiments of Funderburk and Narayanaswamy at North Carolina State University. Single vortex generator and a vortex generator array placed upstream of the shock-induced separation region were investigated. Near wall streamlines, surface pressure contours and density contours on crosswise planes were compared with experiments for flow control using a single vortex generator. Results indicate that the present computations are able to capture the wake and shock structures, and also predict reduction in the streamwise extent of flow separation downstream of the device trailing edge. Finally, the effects of the shape/orientation (forward facing/backward facing) of a single vortex generator, and the design of an array of three vortex generators (with devices of similar and mixed orientations) on the flow separation were also investigated. Contours of near-surface streamwise velocity showed that device orientation had a strong effect on separation control, which is attributed to the differences in the primary streamwise vortices shed in the two cases. Further, the overall reduction in the footprint of separated flow was determined to be most with the use of an array of vortex generators with mixed orientations.}, journal={AEROSPACE SCIENCE AND TECHNOLOGY}, author={Khan, Mohd Shahid Habib and Madabushi, Kasturirangan and Ghosh, Santanu and Edwards, Jack R. and Narayanaswamy, Venkateswaran}, year={2024}, month={Nov} }
 @article{ghosh_2011, title={Economic implications of imputation in agricultural economic data: Discussion}, volume={93}, number={2}, journal={American Journal of Agricultural Economics}, author={Ghosh, S. K.}, year={2011}, pages={627–628} }
 @article{ghosh_choi_edwards_2010, title={Simulation of Shock/Boundary-Layer Interactions with Bleed Using Immersed-Boundary Methods}, volume={26}, ISSN={["0748-4658"]}, DOI={10.2514/1.45297}, abstractNote={This work utilizes an immersed boundary (IB) method to simulate the effects of arrays of discrete bleed ports in controlling shock wave / turbulent boundary layer inter actions . Both Reynolds averaged Navier -Stokes (RANS) and hybrid large -eddy / Reynolds -averaged Navier -Stokes (LES/RANS) turbulence closures are used with the IB technique. The approach is validated by conducting simulations of Mach 2.5 flow over a perfo rated plate containing 18 individual bleed holes. Predictions of discharge coefficient as a function of bleed plenum pressure are compared with experimental data. Simulations of an impinging oblique shock / boundary layer interaction at Mach 2.45 with an d without active bleed control are also performed. The 68 -hole bleed plate is rendered as an immersed object in the computational domain. Wall pressure predictions show that, in general, the LES/RANS technique under -estimate s the upstream extent of axi al separation that occurs in the absence of bleed. Good agreement with P itot -pressure surveys throughout the interaction region is obtained, however. Active suction completely removes the separation region and induces local disturbances in the wall pres sure distributions that are associated with the expansion of the boundary layer fluid into the bleed port and its subsequ ent re -compression. Predicted Pitot -pressure distributions are in good agreement with experiment for the case with bleed. Swirl stre ngth probability -density distributions are used to estimate the evolution of turbulence length -sca les throughout the interaction, and the effects of bleed on the amplification of Reynolds stresses are highlighted. Finally, simple improvements to engineerin g-level bleed models are proposed based on the computational results.}, number={2}, journal={JOURNAL OF PROPULSION AND POWER}, author={Ghosh, Santanu and Choi, Jung-Il and Edwards, Jack R.}, year={2010}, pages={203–214} }
 @article{ghosh_choi_edwards_2010, title={Numerical Simulations of Effects of Micro Vortex Generators Using Immersed-Boundary Methods}, volume={48}, ISSN={["0001-1452"]}, DOI={10.2514/1.40049}, abstractNote={This work presents an immersed-boundary technique for compressible, turbulent flows and applies the technique to simulate the effects of micro vortex generators in controlling oblique-shock/turbulent boundary-layer interactions. The Reynolds-averaged Navier-Stokes equations, closed using the Menter k-ω turbulence model, are solved in conjunction with the immersed-boundary technique. The approach is validated by comparing solutions obtained using the immersed-boundary technique with solutions obtained on a body-fitted mesh and with experimental laser Doppler anemometry data collected at Cambridge University for Mach 2.5 flow over single micro vortex generators. Simulations of an impinging oblique-shock boundary-layer interaction at Mach 2.5 with and without micro vortex-generator flow control are also performed, considering the development of the flow in the entire wind tunnel. Comparisons are made with experimental laser Doppler anemometry data and surface-pressure measurements from Cambridge University and an analysis of the flow structure is performed. The results show that three dimensional effects initiated by the interaction of the oblique shock with the sidewall boundary layers significantly influence the flow patterns in the actual experiment. The general features of the interactions with and without the micro vortex-generator array are predicted to good accord by the Reynolds-averaged Navier-Stokes/ immersed-boundary model.}, number={1}, journal={AIAA JOURNAL}, author={Ghosh, Santanu and Choi, Jung-Il and Edwards, Jack R.}, year={2010}, month={Jan}, pages={92–103} }