Disclosed herein is a valveless multitube pulse detonation engine including: a plurality of detonation tubes, wherein each detonation tube comprises an independent discharge outlet, and the plurality of detonation tubes interconnected at a common air/fuel mixture intake port. In the disclosed engine, an air and fuel mixture is detonated in the detonation tubes simultaneously, and the common air/fuel mixture intake port minimizes back-pressure caused by detonating the air/fuel mixture by directing multiple reverse shock waves into one another and effectively using the back-pressures as reacting surfaces for one another and effectively reducing the effect of back flowing shock waves moving towards upstream. The detonation tubes may be non-linear, and may have independent discharges. The independent discharges may be coupled to an adapter nozzle terminating in a combined exhaust outlet.