Assessment of Numerical Cold Flow Testing of Gas Turbine Combustor through an Integrated Approach using Rapid Prototyping and Water Tunnel 2019-28-0051
In the present work, it is aimed at developing an integrated approach for combustor modeling involving rapid prototyping and water tunnel testing to assess the cold flow numerical simulations; the physical model will be subjected to cold flow visualization and parametric studies and CFD analysis to demonstrate its capability for undergoing rigorous cold flow testing. A straight through annular combustor is chosen for the present study because of it has low pressure drop, less weight and used widely in modern day aviation engines.
Numerical Analysis has been performed using ANSYS-FLUENT. Three dimensional RANS equations are solved using k-ɛ model for the Reynolds numbers ranging from 0.64 x 10^5- 1.5 x 10^5 based on the annulus diameter. Post processing the results is done in terms of jet penetration, formation of re-circulation zone, effective mixing, flow split and pressure drop for different cases. Physical combustor models are fabricated using Rapid prototyping with Poly Lactic Acid material and approximated 2D combustor model is used for capturing important flow patterns using high speed camera in 2D water tunnel, and for pressure measurement in vertical flow water tunnel.
Qualitative flow visualization study on 2D combustor model using 2D water tunnel reasonably compares with CFD results. It is also found that the percentage of total pressure drop normalized with the inlet total pressure of combustor is within the acceptable range (i.e. less than 10%) in CFD whereas in the physical cold flow testing, it has more deviation at the lower flow rate.