cranfield0068

aspect air helium simul hyperson approxim illustr differ may expect result obtain hyperson wind tunnel employ air result obtain employ helium test medium imperfect effect consid compil present herein simpl express present demonstr possibl simul air result helium test transform helium data equival air data nonvisc viscou simul consid case method gener form express simul deriv applic two ideal gase differ ratio specif heat