A fuel system comprising a fuel tank containing hydrocarbon fuel; a hydrocarbon fuel flow path in fluid communication with the fuel tank; a gas separation pump disposed on the flow path, comprising: a pump housing comprising an inner wall defining a cylindrical internal cavity, said pump housing comprising an inlet at a first axial position along the cylindrical cavity outer circumference, an outlet at a second axial position along the cylindrical cavity outer circumference, and a vacuum connection in fluid communication with the cylindrical cavity axis; a first impeller axially disposed between the inlet and the outlet, said first impeller comprising an outer edge configured to sweep along the inner wall; a second impeller axially disposed between the first impeller and the outlet, said second impeller configured to eject liquid through the fluid outlet; and characterized by a thermal management system (24, 36) configured to heat the fuel; a fuel system delivery outlet configured to receive a degassed fuel from the gas separation pump and to deliver it to the thermal management system; the inner wall including a plurality of uneven surface features; the outer edge of the first impeller including a plurality of straight, rib-like structures with sharp edges having a rectangular notch pattern in an axial cross-section, and the plurality of rib-like structures being received in the uneven surface features of the inner wall. a fuel tank containing hydrocarbon fuel; a hydrocarbon fuel flow path in fluid communication with the fuel tank; a gas separation pump disposed on the flow path, comprising: a pump housing comprising an inner wall defining a cylindrical internal cavity, said pump housing comprising an inlet at a first axial position along the cylindrical cavity outer circumference, an outlet at a second axial position along the cylindrical cavity outer circumference, and a vacuum connection in fluid communication with the cylindrical cavity axis; a first impeller axially disposed between the inlet and the outlet, said first impeller comprising an outer edge configured to sweep along the inner wall; a second impeller axially disposed between the first impeller and the outlet, said second impeller configured to eject liquid through the fluid outlet; and characterized by a pump housing comprising an inner wall defining a cylindrical internal cavity, said pump housing comprising an inlet at a first axial position along the cylindrical cavity outer circumference, an outlet at a second axial position along the cylindrical cavity outer circumference, and a vacuum connection in fluid communication with the cylindrical cavity axis; a first impeller axially disposed between the inlet and the outlet, said first impeller comprising an outer edge configured to sweep along the inner wall; a second impeller axially disposed between the first impeller and the outlet, said second impeller configured to eject liquid through the fluid outlet; and characterized by a thermal management system (24, 36) configured to heat the fuel; a fuel system delivery outlet configured to receive a degassed fuel from the gas separation pump and to deliver it to the thermal management system; the inner wall including a plurality of uneven surface features; the outer edge of the first impeller including a plurality of straight, rib-like structures with sharp edges having a rectangular notch pattern in an axial cross-section, and the plurality of rib-like structures being received in the uneven surface features of the inner wall.