A pulse detonation (PD) assembly includes at least one PD chamber having a wall, which defines cooling holes arranged along at least a portion of the PD chamber. A manifold extends around the PD chamber. The manifold and PD chamber are separated by a bypass region. A PD assembly with reverse flow cooling includes at least one PD chamber. A sleeve extends around the PD chamber. The sleeve and PD chamber are separated by a reverse flow cooling passage configured to receive a flow of air and to flow the air in a reverse direction to supply the PD chamber. A PD assembly with bypass flow cooling includes at least one PD chamber and a manifold extending around the PD chamber(s), which are separated by a bypass region. The PD assembly further includes a mixing plenum configured to receive and mix the bypass flow from the bypass region and the detonation by-products from the PD chamber(s).