Verdú-Andrés, S. Belomestnykh, S.A. Wang, J. Wu, Q. Xiao, B. P. JACoW Geneva, Switzerland 978-3-95450-178-6 10.18429/JACoW-SRF2015-THPB051 English 1215-1218 THPB051 cavity simulation radiation vacuum electromagnetic-fields Contribution to a conference proceedings 2015 2015-12 http://dx.doi.org/10.18429/JACoW-SRF2015-THPB051 http://srf2015.vrws.de/papers/thpb051.pdf The Lorentz detuning is the resonant frequency change in an RF cavity due to the radiation pressure on the cavity walls. We present benchmarking studies of Lorentz detuning calculations for a Double-Quarter Wave Crab Cavity (DQWCC) using the codes ACE3P. The results are compared with the Lorentz detuning measurements performed during the cold tests of the Proof-of-Principle DQWCC at BNL.