Publications
Journals
A. L. N. Prasad, and S. Unnikrishnan, '' Noise mitigation in rectangular jets through plasma actuator based shear layer control'', January 2024, Journal of Fluid Mechanics, 979, A60.
K. Aswathy Nair, and S. Unnikrishnan, "Effects of Nose Bluntness on Hypersonic Transition over Ogive-Cylinder Forebodies", October 2023, AIAA Journal, https://doi.org/10.2514/1.J063130.
S. Unnikrishnan, "Recent advances in feature extraction techniques for high-speed flowfields", June 2023, Progress in Aerospace Sciences, https://doi.org/10.1016/j.paerosci.2023.100918.
A. L. N. Prasad, and S. Unnikrishnan, "Effect of plasma actuator-based control on flow-field and acoustics of supersonic rectangular jets", 2023, Journal of Fluid Mechanics, 964, A11.
H. Goparaju, K. Kanawade, S. Unnikrishnan, and D. Gaitonde, "Linear and Nonlinear Disturbance Evolution on the Frustum of Hypersonic Ogive Cylinders", AIAA Journal, 2023, https://doi.org/10.2514/1.J062534, 1-13.
N. Khobragade, S. Unnikrishnan, and R. Kumar, "Flow Instabilities and Impact of Ramp-Isolator Junction on Shock/Boundary-Layer Interactions in a Supersonic Intake", Journal of Fluid Mechanics, Volume 953, December 2022, A30.
A. Prasad, Y. Saleh, P. Sellappan, S. Unnikrishnan and F. Alvi, "Effects of Expansion Ratio and Nozzle Asymmetry on Flowfield of Diamond Jets", Published Online:30 May 2022, DOI: https://doi.org/10.2514/1.J061624.
S. Chakrabarti, D. Gaitonde, S. Unnikrishnan, C. Stack, F. Baier, A. Karnam and E. Gutmark, "Turbulent Statistics of a Hot, Overexpanded Rectangular Jet", Journal of Propulsion and Power, Volume 38, Number 3 May 2022.
S. Unnikrishnan and D. Gaitonde, "Perturbation Analysis of Nonlinear Stages in Hypersonic Transition", September 2021 International Journal of Computational Fluid Dynamics 35(5):306 - 318.
S. Chakrabarti, D. Gaitonde, and S. Unnikrishnan, "Representing rectangular jet dynamics through azimuthal Fourier modes", July 2021 Physical Review Fluids 6(7).
N. Khobragade, S. Unnikrishnan, and R. Kumar, ``Linear and Nonlinear Flow-Analysis of Elements of a Supersonic Inlet'', AIAA Journal, Volume 59, Number 11, November 2021.
R. Ranjan, S. Unnikrishnan, J.-C. Robinet, and D. Gaitonde, "Global transition dynamics of flow in a lid-driven cubical cavity", Theoretical and Computational Fluid Dynamics, 2021.
H. Goparaju, S. Unnikrishnan, and D. Gaitonde, "Effects of nose bluntness on hypersonic boundary-layer receptivity and stability", Journal of Spacecraft and Rockets, In press.
S. Unnikrishnan, and D. Gaitonde, "Instabilities and transition in cooled-wall hypersonic boundary layers", Journal of Fluid Mechanics, Volume 915, May 2021, A26.
S. Unnikrishnan, and D. Gaitonde, "Linear, nonlinear and transitional regimes of second-mode instability", Journal of Fluid Mechanics, Volume 905, October 2020.
S. Unnikrishnan, and D. Gaitonde, "A pressure decomposition framework for aeroacoustic analysis of turbulent jets", European Journal of Mechanics / B Fluids, Volume 81, 2020, pp. 41 - 61.
R. Ranjan, S. Unnikrishnan, and D. Gaitonde, "A robust approach for stability analysis of complex flows using high-order Navier-Stokes solvers", Journal of Computational Physics, Volume 403, 2020, pp. 109076.
S. Unnikrishnan, and D. Gaitonde, "First-mode-induced nonlinear breakdown in a hypersonic boundary layer", Computers & Fluids, Volume 191, 2019, pp. 104249.
S. Unnikrishnan, A. V. G. Cavalieri and D. Gaitonde, "Acoustically informed statistics for wavepacket models", AIAA Journal, Volume 57, 2019, pp. 2421 - 2434.
S. Unnikrishnan and D. Gaitonde, "Interactions between Vortical, Acoustic and Thermal Components during Hypersonic Transition", Journal of Fluid Mechanics, Volume 868, June 2019, pp. 611 - 647.
S. Bhaumik, D. Gaitonde, S. Unnikrishnan, A. Sinha, H. Shen, "Verification and Application of a Mean Flow Perturbation Method for Jet Noise", Aerospace Science and Technology, Volume 80, September 2018, pp. 520 - 540.
S. Unnikrishnan and D. Gaitonde, "Transfer mechanisms from stochastic turbulence to organized acoustic radiation in a supersonic jet", European Journal of Mechanics-B/Fluids, Volume 72, November - December 2018, pp. 38 - 56.
S. Unnikrishnan, K. Goparaju and D. Gaitonde, "Energy-Dynamics Resulting in Turbulent and Acoustic Phenomena in an Underexpanded Jet", Aerospace, Volume 5(2), May 2018.
S. Unnikrishnan, D. Gaitonde and L. Agostini, "Directivity and intermittency in the nearfield of a Mach 1.3 jet", International Journal of Aeroacoustics, Volume 16(3), June 2017, pp. 135-164.
S. Unnikrishnan and D. Gaitonde, "Acoustic, Hydrodynamic and Thermal Modes in a Supersonic Cold Jet", Journal of Fluid Mechanics, Volume 800, August 2016, pp. 387 - 432.
S. Unnikrishnan and D. Gaitonde, "A high-fidelity method to analyze perturbation evolution in turbulent flows", Journal of Computational Physics, Volume 310, 1 April 2016, pp. 45-62.
T. K. Sengupta, S. Unnikrishnan, S. Bhaumik, P. Singh, S. Usman, "Linear Spatial Stability Analysis of Mixed Convection Boundary Layer over a Heated Plate", Progress in Applied Mathematics, Vol. 1, No. 1, 2011, pp. 71-89
Conferences
K. Aswathy Nair, and S. Unnikrishnan, ''Investigation of transition mechanisms in blunt-tip ogive-cylinder forebodies'', (AIAA 2024-2182), AIAA Science and Technology Forum and Exposition 2024, (SciTech, 2024).
G. Dashora, and S. Unnikrishnan, ''Effects of inflow boundary layer on supersonic inlets'', (AIAA 2024-1385), AIAA Science and Technology Forum and Exposition 2024, (SciTech, 2024).
A. L. N. Prasad, and S. Unnikrishnan, ''Flow-field and Acoustics of Over-expanded Rectangular Jets Subjected to LAFPA Based Control '',(AIAA 2024-2304), AIAA Science and Technology Forum and Exposition 2024, (SciTech, 2024).
K. Kanawade, S. Unnikrishnan and D. Gaitonde, ''Effect of geometric and thermal parameters on sensitivity and stability of ogive-cylinder forebody flows '', (AIAA 2023-4178), AIAA Aviation Forum, (Aviation, 2023).
A. L. N. Prasad, and S. Unnikrishnan, ''Flow-field and Acoustics of Azimuthally Forced Rectangular Jets'', (AIAA 2023-4178), AIAA Aviation Forum, (Aviation, 2023).
A. L. N. Prasad, and S. Unnikrishnan, ''Effect of LAFPA Based Control on Supersonic Rectangular Jets'', (AIAA 2023-1346), AIAA Science and Technology Forum and Exposition 2023, (SciTech, 2023).
A. L. N. Prasad, Y. Saleh, P. Sellappan, S. Unnikrishnan, F. Alvi, ''Near-field and far-field effects of heating in an over-expanded Mach 2 diamond jet'', (AIAA 2022-), AIAA Science and Technology Forum and Exposition 2022, (SciTech, 2022).
N. Khobragade, S. Unnikrishnan and R. Kumar, "Stability Analysis of Supersonic Flows Over a Modified Backward Facing Step", (AIAA 2021-1654), AIAA Science and Technology Forum and Exposition 2021, (SciTech, 2021).
Y. Saleh, P. Sellappan, S. Unnikrishnan and F. Alvi, "Experimental and Computational Study of a Mach 2 Diamond Jet", (AIAA 2021-1523), AIAA Science and Technology Forum and Exposition 2021, (SciTech, 2021).
S. Chakrabarti, D. Gaitonde, and S. Unnikrishnan "The Dynamics of Azimuthal Modes in Rectangular Jets", (AIAA 2020-3000), AIAA Aviation Forum, (Aviation, 2020).
S. Unnikrishnan, and D. Gaitonde, "Instability characteristics of cooled hypersonic boundary layers", (AIAA 2020-0588), AIAA Science and Technology Forum and Exposition 2020, (SciTech, 2020).
H. Goparaju, S. Unnikrishnan, and D. Gaitonde, "Effects of nose bluntness on hypersonic boundary layer receptivity and stability", (AIAA 2020-1818), AIAA Science and Technology Forum and Exposition 2020, (SciTech, 2020).
S. Chakrabarti, S. Unnikrishnan, D. V. Gaitonde, C. Stack, F. Baier, A. Karnam and E. Gutmark, "On the Turbulence Statistics of a Hot, Overexpanded Rectangular Jet", (AIAA 2020-0819), AIAA Science and Technology Forum and Exposition 2020, (SciTech, 2020).
S. Unnikrishnan, and D. Gaitonde, "Fluctuating-enthalpy source mechanisms of first- and second-mode oscillations in a hypersonic boundary layer", (AIAA 2019-0892), AIAA Science and Technology Forum and Exposition 2019, (SciTech, 2019).
S. Bhaumik, D. Gaitonde and S. Unnikrishnan, "Verification and Application of a Mean Flow Perturbation Method for Jet Noise", AA2/07, Paper Presented in WESPAC (Western Pacific Commission for Acoustics) meeting titled "Acoustical Science and Technology for Quality of Life" held at CSIR National Physical Laboratory (CSIR-NPL), New Delhi-110012, from 11-15 November, 2018.
S. Unnikrishnan, A. V. Cavalieri and D. Gaitonde, "Acoustically informed statistics for wavepacket models", (AIAA 2018-3466), 2018 AIAA/CEAS Aeroacoustics Conference, AIAA Aviation Forum, 10.2514/6.2018-3466 (Aviation, 2018).
R. Ranjan, S. Unnikrishnan and D. Gaitonde, "On the Use of Mean Flow Perturbation for Global Stability Analysis", (AIAA 2018-3378), 2018 Fluid Dynamics Conference, AIAA Aviation Forum, 10.2514/6.2018-3378 (Aviation, 2018).
K. Goparaju, S. Unnikrishnan and D. Gaitonde, "Acoustic Characteristics of a Supersonic Twinjet Configuration", (AIAA 2018-3304), 2018 AIAA/CEAS Aeroacoustics Conference, AIAA Aviation Forum, 10.2514/6.2018-3304 (Aviation, 2018).
S. Unnikrishnan and D. Gaitonde, "Kovasznay-Type Analysis of Transition Modes in a Hypersonic Boundary Layer", (AIAA 2018-2086), AIAA Aerospace Sciences Meeting, 2018, 10.2514/6.2018-2086 (SciTech, 2018).
S. Unnikrishnan and D. Gaitonde, "The Acoustic Mode and its Sources in a Supersonic Jet", (AIAA 2017-0685), 55th AIAA Aerospace Sciences Meeting, 2017, 10.2514/6.2017-0685 (SciTech, 2017).
S. Bhaumik, D. Gaitonde, K. Goparaju, S. Unnikrishnan, and M. Waindim, "Application of NavierStokes based Mean-Flow Perturbation Method to Supersonic Jet Noise", (AIAA 2016-4092), 2016 AIAA Fluid Dynamics Conference, AIAA Aviation Forum.
S. Unnikrishnan and D. Gaitonde, "Fluid-Thermodynamic Mode Decomposition of a Supersonic Jet", 22nd AIAA/CEAS Aeroacoustics Conference, Lyon, France, May, 2016, 10.2514/6.2016-2941.
S. Sengupta, L. Agostini , S. Unnikrishnan and D. Gaitonde, "Investigation of Rectangular Jet Issuing From a Varying Cross-Section Nozzle", (AIAA 2016-1110), 54th AIAA Aerospace Sciences Meeting, 2016, 10.2514/6.2016-1110 (SciTech, 2016).
S. Unnikrishnan, L. Agostini and D. Gaitonde, "Scale-specific Intermittency and Spatio-temporal Correlations in a Supersonic Jet"(AIAA 2016-0005), 54th AIAA Aerospace Sciences Meeting, 2016, 10.2514/6.2016-0005 (SciTech, 2016).
S. Unnikrishnan, L. Agostini and D. Gaitonde, "Analysis of Intermittency of Supersonic Jet Noise with Synchronized LES", (AIAA 2015-2532), 21st AIAA/CEAS Aeroacoustics Conference, 2015, 10.2514/6.2015- 2532 (Aviation, 2015).
S. Unnikrishnan and D. Gaitonde, "Synchronized Large-Eddy Simulations to track Native Perturbations in a Turbulent Jet", (AIAA 2015-0505), 53rd AIAA Aerospace Sciences Meeting, 2015, 10.2514/6.2015- 0505 (SciTech, 2015).
S. Unnikrishnan and D. Gaitonde, “Synchronized Large-Eddy Simulations for Sound Generation Analysis”, IUTAM Symposium on Advances in Computation and Modeling of Transitional and Turbulent Flows, Dec 15-18, Goa, 2014.