Measurements of End Thrust on a Model Poppet Exhaust Valve

Abstract

End thrust measurements have been made under steady flow conditions on a model poppet exhaust valve supported on air bearings in a straight ‘port’ coaxial with a ‘cylinder’. The tests covered pressure ratios across the valve up to 1·75. They show that the end thrust is approximately equal to the product of the pressure drop and the exposed head area, for lifts up to about 0·15 diameters, and diminishes progressively with increase of lift beyond that value.