A systematic investigation was made of the differences in atomizing performance between water and kerosene fuel for six simplex fuel nozzles of small flow capacity. A large number of tests was run using two methods of spray analysis, to determine the effect of nozzle liquid pressure drop (ΔP F ) on Sauter Mean Diameter (SMD). It was found that there is a clearly-defined relationship dependent on both the relative values of surface tension and also on a Weber Number calculated for conditions in the liquid film at the nozzle discharge orifice. It is concluded that large errors in estimating SMD for modeling programs are possible if results observed with water are assumed to be representative of behavior with kerosene fuel.

A little used parameterization of the three-dimensional rotation group is taken as basis in deriving an easily integrable kinematic relation (a 4-vector linear differential equation) for the attitude rate, in terms of the present attitude and angular velocity of one reference frame relative to another. If the angular velocity is known and well behaved one obtains the exact solution from an iteration procedure explained in detail. The formal solution to a large class of rigid-body problems is thus implied; a particular one being that of an axially symmetric rocket with variable thrust vector and constant moment-of-inertia tensor which as such generalizes Jacobi’s torque-free case.