Abstract
Two iterative subspace methods (Arnoldi and Jacobi-Davidson) are compared for solving typical quadratic eigenvalue problems arising when studying combustion instabilities. An academic, representative test case is presented with associated analytical solution. The efficiency of the iterative methods is studied in terms of running time when 1-10 eigenpairs are sought for, the computational domain being discretized with 500-32000-node finite element meshes. The sensitivity of the methods to the dimension of the search subspace is also investigated.