This　study　aims　to　explore　the　influence　of　hydrogen　injection　parameters　on　the　flow　field　and　combustion　characteristics　in　Wankel　rotary　engines.　The　numerical　results　showed　that　the　area　of　high-speed　hydrogen　jet　flow　in　the　combustion　chamber　decreased　when　the　hydrogen　injection　timing　(HIT)　was　delayed　to　390　degrees　of　eccentric　angle.　This　weakened　the　mixing　process　in　the　combustion　chamber　but　resulted　in　a　lower　residual　gas　in　the　ignition　chamber　at　the　end　of　injection.　However,　a　lean　mixture　area　was　formed　at　the　rear　end　of　the　combustion　chamber.　When　the　HIT　was　changed,　the　velocity　and　turbulent　kinetic　energy　(TKE)　fields　at　the　ignition　timing　were　almost　the　same.　The　distribution　of　the　equivalence　ratio　significantly　impacted　the　initial　flame　kernel,　whereas　TKE　had　minimal　influence.　When　the　hydrogen　nozzle　diameter　(HND)　was　increased　to　4　mm　and　the　injection　pressure　(HIP)　was　raised　to　10　MPa,　the　size　of　the　high-velocity　zone　and　the　mass　of　leakage　gas　were　increased.　When　the　concentration　of　hydrogen　near　the　leading　spark　plug　was　high,　it　could　cause　the　rapid　consumption　of　the　unburned　mixture　in　the　front　part　of　the　combustion　chamber.　The　high-temperature　and　high-pressure　mixture　generated　by　the　instantaneous　heat　release　accelerated　the　flame　propagation　to　the　back　part　of　the　combustion　chamber,　thus　leading　to　the　occurrence　of　knock.　©　2025　Elsevier　Ltd