Would a medieval pulse jet engine have been possible to propel a small boat?

Sorry this may be dumb but I’m writing a story set in the 13th century CE and wondering if a bronze pulse jet (in my story basically just a metal tube, but perhaps one bent into a U-shape) using 2 fictional liquids fed in that combine to ignite in a hypergolic reaction could be possible to believably propel a small boat. I only need the engine to last a few hours.