Low　flow　rate　is　one　of　the　primary　disadvantages　of　Roots　pumps　when　they　are　applied　in　hydrogen　fuel　cell　vehicles.　A　novel　profile　for　Roots　pumps　was　developed　in　this　paper　to　increase　the　working　volume　and　reduce　the　internal　leakage.　The　available　range　of　the　design　parameters　of　the　Roots　pump　with　the　new　profile　was　determined　analytically,　and　an　improvement　in　the　working　volume　was　validated.　The　flow　dynamics　inside　the　traditional　and　new　pumps　were　investigated　by　experiments　and　numerical　simulations.　The　analytical　results　indicated　that　the　maximum　area　utilization　of　the　new　profile　was　approximately　10.4%　higher　than　that　of　the　traditional　profile　at　the　same　lobe　number.　The　numerical　results　demonstrated　the　superiority　of　the　proposed　profile　in　high　flow　rate　and　sealing.　The　tip　concentric　arcs　of　the　new　profile　reduced　the　internal　leakage　via　the　radial　gap.　The　characteristic　of　multipoint　meshing　within　a　certain　range　of　rotational　angles　reduced　the　interlobe　leakage.　(c)　2021　Hydrogen　Energy　Publications　LLC.　Published　by　Elsevier　Ltd.　All　rights　reserved.