Numerical Investigation of Transverse Forcing in a Multi-Element, Shear-Coaxial, High Pressure Combustor

Numerical investigation of transverse combustion instability is conducted in a rectangular combustion chamber using large eddy simulations. The combustion chamber is a multi-element, shear-coaxial, high pressure combustor, referred as transverse instability combustor (TIC) rig, which is experimentally studied at Purdue University. We consider a reduced geometrical representation of the rig, where we model three out of the seven injector elements in order to assess the capability to reproduce the first mode transverse instability observed within the TIC rig, at a reduced computational cost. The use of characteristic boundary conditions permits to study the same case with an imposed pressure oscillation. We analyze the results from both test cases to investigate similarities and differences in terms of thermo-acoustic quantities, and provide useful insights for future studies.