Context: Recently, the Indian Space Research Organisation (ISRO) has developed Computational Fluid Dynamics (CFD) software named Parallel RANS Solver for Aerospace Vehicle Aero-thermo-dynamic Analysis (PraVaHa).

About PraVaHa

• PraVaHa is a Computational Fluid Dynamics (CFD) software developed by the Indian Space Research Organisation (ISRO) at the Vikram Sarabhai Space Centre (VSSC).

• It's designed to simulate airflow around various aerospace vehicles, including launch vehicles, re-entry vehicles with and without wings, and internal flows.

• Currently, it can simulate airflow under both Perfect Gas and Real Gas conditions. Work is ongoing to simulate chemical reactions during air dissociation and combustion, particularly relevant for scramjet vehicles.

Need of PraVaHa

• PraVaHa is crucial for initial aerodynamic design studies of launch vehicles, as it evaluates numerous configurations efficiently.

• Aerospace vehicles face severe aerodynamic and aerothermal loads during launch and re-entry due to external pressure and heat flux. PraVaHa helps in understanding and predicting these loads.

• It's vital for designing the shape, structure, and Thermal Protection System (TPS) required for these vehicles.

• The software is also used to address issues like unsteady aerodynamics and acoustic noise generated during missions.

Significance

• Gaganyaan Programme: PraVaHa has been used extensively in the Gaganyaan program for aerodynamic analysis of human-rated launch vehicles, viz, HLVM3, Crew Escape System (CES), and CM.

• Scramjet Vehicles: Validations of the code are underway for simulating the effect of chemical reactions that occur during air dissociation upon ‘earth re-entry’ and ‘combustion’ as in scramjet vehicles.

• Replacement of CFD Simulations: PraVaHa is expected to replace most of the CFD simulations for aero characterisation, which is currently being carried out using commercial software. 

• Solutions to Complex Aerodynamic Problems: This software is expected to help academia and other institutions, engaged in the design of missiles, aircraft and rockets, to find solutions to complex aerodynamic problems.

• It's not only beneficial for ISRO's programs like Gaganyaan but also aids academia and other institutions working on missile, aircraft, and rocket design.

Additional Information

About Computational Fluid Dynamics (CFD)

• A Tool for Prediction: CFD is a tool to predict the aerodynamic and aerothermal loads which solve numerically the equations of conservation of mass, momentum, and energy along with the equation of state.