effect of oxidizer to fuel ratio on tank mass and thickness for liquid fuel dimethyl aminoethyl azide (dmaz) with some oxidizers in space programs

Dimethyl aminoethyl azide (dmaz), as a novel liquid fuel, is a good candidate for use in the upper stage of space rockets. one of the new features for the liquid fuel with conventional liquid oxidizers ak27 and nitrogen tetroxide (nt) is the dry mass estimation of tanks and thickness used for the tanks of dmaz/ak27 and dmaz/nt bipropellants through simple relations instead of complex relations. the oxidizer to fuel (o/f) ratio, as an important parameter, was applied for the estimations. in other words, the summation of the dry mass of tanks and bipropellants was calculated at certain values of o/f ratios. moreover, the application of this simple method was developed for liquid fuels monomethyl hydrazine (mmh) and unsymmetrical dimethyl hydrazine (udmh) with the liquid oxidizers. rpa software was used to find the optimum o/f ratio. the results showed that at a combustion chamber pressure of 15 bar, exit pressure of 0.001 bar, operation time of 480 seconds, and 7kn thrust, the lowest and the highest dry masses belong to nt/dmaz and nt/mmh propellant tanks, respectively. also, nt/mmh and ak27/dmaz have the lowest and highest summation masses, respectively.