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Projects: Projects for Investigator
Reference Number EP/W026090/1
Title Turbulent flows over rough-walls under the influence of streamwise pressure gradients
Status Started
Energy Categories Renewable Energy Sources(Wind Energy) 20%;
Not Energy Related 80%;
Research Types Basic and strategic applied research 100%
Science and Technology Fields PHYSICAL SCIENCES AND MATHEMATICS (Applied Mathematics) 50%;
ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering) 50%;
UKERC Cross Cutting Characterisation Not Cross-cutting 100%
Principal Investigator Dr B (Bharathram ) Ganapathisubramani
No email address given
School of Engineering Sciences
University of Southampton
Award Type Standard
Funding Source EPSRC
Start Date 01 April 2023
End Date 31 March 2026
Duration 36 months
Total Grant Value £861,714
Industrial Sectors No relevance to Underpinning Sectors
Region South East
Programme NC : Engineering
Investigators Principal Investigator Dr B (Bharathram ) Ganapathisubramani , School of Engineering Sciences, University of Southampton (99.999%)
  Other Investigator Professor ND Sandham , School of Engineering Sciences, University of Southampton (0.001%)
  Industrial Collaborator Project Contact , European Office of Aerospace Research and Development (EOARD) (0.000%)
Web Site
Abstract The efficiency and performance of an aerodynamic surface (wind turbine blade or a ship rudder) is a trade-off between the lift generated and the drag incurred by it. The required lift force is attained by changing the shape and orientation of the geometry, which generates a pressure and load distribution along its length. The drag incurred depends on the characteristics of the turbulent boundary layer flow that develops over the surface. Unfortunately, these two design requirements are not independent of each other as the turbulent boundary layer depends on the overlying non-zero pressure gradient due to the pressure distribution. Additionally, the boundary layer flow also depends on the topographical features (or roughness) of the surface where features as small as 10 microns are considered to be hydrodynamically "rough". This situation where the boundary layer flow is under the influence of both non-zero pressure gradient and surface roughness is pervasive in engineering and environmental applications. Examples include flow over airfoils/turbine blades, ducts, flow over/around buildings, hills/valleys etc. Despite its prevalence, the effects of pressure gradient on flow over rough surfaces remains largely unexplored. As we strive towards net zero carbon emissions by 2050, it is timely to develop new understanding and modelling strategies that capture the influence of pressure gradients on the performance of flow over rough surfaces. In this project, we aim to characterise the evolution of non-zero pressure gradient (PG) turbulent boundary layers (TBL) over rough surfaces and thereby identify the parameters that dictate the response of boundary layers to streamwise pressure gradients. A comprehensive series of wind-tunnel experiments and numerical simulations will be performed to generate unprecedented data on flow over rough-walls subject to favourable and adverse pressure gradients (FPG and APG). The data will underpin identification and validation of potential universalities (and differences) in mechanisms of momentum/energy transfer compared to zero-pressure-gradient (ZPG) flows. The data will then be used to develop and validate both integral models and new Large-Eddy Simulation (LES) models that can be used to predict the performance of flow over arbitrary rough surfaces under the influence of varied pressure gradients. The data will be made available in the public domain through our roughness database (www.roughnessdatabase.org). The overall aim is to establish the interrelationship between roughness and pressure gradients over a broad range of parameters (for pressure gradient and roughness properties), understand the limitations of current models and develop new modelling methods that can be used for predictions in a wide range of applications
Publications (none)
Final Report (none)
Added to Database 19/04/23