Towards Practically Deployable Drag Reduction Strategies for High-Speed Transportation

Upstream history quantification and scale-decomposed energy analysis for weak-to-strong adverse-pressure-gradient turbulent boundary layers

A Mahajan, R Deshpande, TR Gungor, Y Maciel, R Vinuesa

2026-01-01

The present study delineates the effects of pressure gradient history and local disequilibration on the small and large-scale ener..

Investigation of turbulent/non-turbulent interfaces in high Reynolds number adverse pressure gradient boundary layers

L Lindić, WA Rowin, R Deshpande, I Marusic

2025-08-01

This study utilises high-magnification two-dimensional Particle Image Velocimetry (2D-PIV) to investigate adverse pressure gradien..

Response of a turbulent boundary layer to steady, square-wave-type transverse wall-forcing

MW Knoop, R Deshpande, FFJ Schrijer, BW Van Oudheusden

2025-06-01

This study investigates the spatial evolution of a zero pressure gradient turbulent boundary layer (TBL) imposed by a square-wave ..

High-fidelity simultaneous measurements of velocity and temperature fluctuations using a dual-wire sensor within thermal boundary layers

Y Xia, WA Rowin, R Deshpande, I Marusic, N Hutchins

2025-05-31

A customised dual-wire sensor, incorporating both a cold-wire and a hot-wire, has been developed to enable simultaneous measuremen..

Experimental characterisation of Kelvin-Helmholtz rollers over riblet surfaces

W Abu Rowin, R Deshpande, S Wang, M Kozul, D Chung, RD Sandberg, N Hutchins

2025-04-28

The formation of Kelvin-Helmholtz-like rollers (referred to as K-H rollers) over riblet surfaces has been linked to the drag-incre..

Active and inactive contributions to the wall pressure and wall-shear stress in turbulent boundary layers

Rahul Deshpande, Ricardo Vinuesa, Joseph Klewicki, Ivan Marusic

2025-01-25

A phenomenological description is presented to explain the intermediate and low-frequency/large-scale contributions to the wall-sh..

Identifying regions of importance in wall-bounded turbulence through explainable deep learning

A Cremades, S Hoyas, R Deshpande, P Quintero, M Lellep, WJ Lee, JP Monty, N Hutchins, M Linkmann, I Marusic, R Vinuesa

2024-12-01

Despite its great scientific and technological importance, wall-bounded turbulence is an unresolved problem in classical physics t..

Streamwise energy-transfer mechanisms in zero- and adverse-pressure-gradient turbulent boundary layers

Rahul Deshpande, Ricardo Vinuesa

2024-10-01

The present study investigates streamwise (Farmula Presented) energy-transfer mechanisms in the inner and outer regions of turbule..

Near-Wall Flow Statistics in High- Reτ Drag-Reduced Turbulent Boundary Layers

R Deshpande, A Zampiron, D Chandran, AJ Smits, I Marusic

2024-06-01

Manipulating the organized flow in the near-wall region of a turbulent boundary layer is a direct path to achieving skin-friction ..

Pressure drag reduction via imposition of spanwise wall oscillations on a rough wall

Rahul Deshpande, Aman G Kidanemariam, Ivan Marusic

2024-01-11

The present study tests the efficacy of the well-known viscous drag reduction strategy of imposing spanwise wall oscillations to r..

Revisiting amplitude modulation in non-canonical wall-turbulence through high-Reynolds number experimental data

Mitchell Lozier, Ivan Marusic, Rahul Deshpande

2024-01-01

The amplitude modulation phenomena, defined originally by Mathis et al. [J. Fluid Mech. 628, 311 (2009)], corresponds to a unique ..

Reynolds-number effects on the outer region of adverse-pressure-gradient turbulent boundary layers

R Deshpande, A Van Den Bogaard, R Vinuesa, L Lindić, I Marusic

2023-12-01

We study the Reynolds-number effects on the outer region of moderate adverse-pressure-gradient (APG) turbulent boundary layers (TB..

On the relationship between manipulated inter-scale phase and energy-efficient turbulent drag reduction

R Deshpande, D Chandran, AJ Smits, I Marusic

2023-09-26

We investigate the role of inter-scale interactions in the high-Reynolds-number skin-friction drag reduction strategy reported by ..

Evidence that superstructures comprise self-similar coherent motions in high Reynolds number boundary layers

Rahul Deshpande, Charitha M de Silva, Ivan Marusic

2023-08-11

We present experimental evidence that the superstructures in turbulent boundary layers comprise smaller, geometrically self-simila..