Experimental estimation of residual propellant in the fuel tanks with innertank capillary devices for spacecraft propulsion systems

Abstract

The paper presents the results of experimental studies of the processes of emptying the fuel tanks of spacecraft liquid rocket propulsion systems at the final stages of free (undisturbed) flight in tanks with innertank capillary devices (IT CD). On the basis of the analysis of the emptying process, the dimensionless complex structure is formed. The complexes determine the dependence of the residual propellant on the physical properties of the propellant and the parameters of the IT CD. Experimental studies were performed on the weightlessness stand, using the principle of realization of the conditions of reduced weight in tested equipment free fall. The results of the experimental studies have shown that the main criterion determining the value of residual propellant is the Froude number. The criterion equation for determination of residual propellant is obtained. The influence of viscosity and surface tension of the propellant on the value of residual propellant begins to affect at the values of the Froude numbers exceeding 104.