This paper summarizes the results of a computer simulation of an acoustic Helmholtz resonator and comparison of those results with experimental data. A commercial CFD code has been used to model, solve, and analyze the simulation. The goal of these efforts is to provide an inexpensive and reliable method for studying oscillating-flow minor losses affecting the performance of thermoacoustic engines. Although there are extensive catalogs of minor losses in steady flow, very little work has been done in oscillatory flow. Researchers at Los Alamos National Laboratory have constructed an acoustic Helmholtz resonator that will allow them to observe oscillating flow losses of common pipe fittings including straight pipes, elbows, diffusers, and t-junctions. The computer model discussed in this paper is designed to closely mirror the experiment being run in the laboratory. By combining the results of the experiment with those of the computer model, scientists hope to learn how to further reduce operating losses of thermoacoustic engines or other oscillating-flow machines.