We simulate time harmonic flows by the lattice Boltzmann method. We propose a general scheme to choose simulation parameters, under the constraints of fixed Reynolds and Womersley numbers, and with a specified simulation error. Under these constraints parameters are chosen to minimize the execution time. Numerical stability is studied in a range of Reynolds and Womersley numbers. As an example of time harmonic flow simulations, results of blood flow in a human abdominal aorta are presented.