ESR2 | Himpu Marbona

Fluid passing geometries will have several properties, such as pressure, shear stress, local velocity, temperature, etc. These properties define the aerodynamic performance of the geometry.

The research focus of the fellow is to understand how properties of the fluid can be affected by a disturbance. Disturbance in a flow can be in a lot of forms, such as an imperfection in the incoming flow or turbulence, a time variation in the inflow condition, and an additional flow introduce at a certain location. This problem is generally known as hydrodynamic stability. Several methodologies are available for stability analysis and most of them depend on the availability of base flow. Baseflow is the initial state of the flow before disturbance is being introduced, which in some cases is a steady solution.

However, if there is no steady solution, which is the most cases, most methodologies depend on the statistically mean flow. Hence, the fellow initial focus is to develop novel methodologies for stability analysis of turbulent three-dimensional flows without statistical mean flow. The tool will have a benefit in understanding the evolution of laminar to turbulent flows, and optimal disturbances to improve performance. A flow typical of low-pressure turbines will be used as the industrial test case.

Using the above tool and methodologies, the research should then move to sensitivity analysis. Its focus is to obtain sensitivity maps of complex laminar-turbulent flows in 3D geometries by developing sensitivity tools that account for the modification of the base flow due to optimal disturbance, external forcing, or surface deformation. These sensitivity maps would have the benefit to provide input in the flow control technologies, such as an optimal location for vortex generators and/or optimal selection of parameters in surface waviness to control the transition to turbulent. Some adjustment to the research activity is expected but would remain within the spirit above.