ALT Figure 1. (Top) Randomly generated combustor geometry consisting of three modules with a flow passing through from left to right. The axial locations of the inlet, flame, and outlet are depicted by blue, red, and green vertical lines, respectively. (Bottom) Corresponding map obtained using OSCILOS with n = .875 and τ = 4.90 ms. A white star indicates the presence of a thermoacoustic mode for that frequency and growth rate.