Utvikling og testing av småskala rakettmotorer for ytelsesmålinger

Equipment consisting of a small scale test-motor and a firing stand has been constructed. During the firing thrust and chamber-pressure were measured simultaneously. The efficiency parameters specific impulse (Isp), characteristic exhaust velocity (c*) and thrust coefficient (Cf) were calculated from the firing curves. Two different propellant grains, one with a relatively constant burning area and one with a progressive burning area, have been tested together with two propellant compositions with different theoretical performance. It was found that measured and theoretical values were consistent. The accuracy of the results did not depend on the grain category used. The results showed also that it was possible to distinguish between measured Isp from two different propellant compositions, even though the theoretical difference in Isp was only about 1%.