Flame propagation through a fuel-air mixture is governed by heat transfer, chemical reaction and mixing processes. For a specific mixture at given levels of pressure and temperature, the first two processes are substantially fixed, and any change in flame propagation rate must be accomplished through manipulation of the mixing processes. Mixing results primarily from diffusion, from the buoyant motion of the hot products of combustion upward through the colder mixture, and from the generation of turbulence by the rapid expansion of the fuelair mixture as it burns. Except in static (nonflowing) systems, the buoyant effects of hot gas in a gravitational field of 1 g are largely overshadowed by the other forces. Centrifugal and gravitational forces act on mass in a similar manner, however, and it is possible to conduct a combustion process in a centrifugal field which will greatly increase the buoyant force acting on the hot products of combustion. The buoyant force per unit volume can be expressed by the equation F=ρC(1−Tc/Th). For typical values of normal air density, a temperature ratio of 5 and a centrifugal field of 1000 g, the buoyant force is 9100 newtons per cubic meter (57.9 lbf/ft2). To investigate the phenomenon experimentally, a centrifuge consisting of a steel pipe 5.1 cm (2 in.) in diameter and 1.26 m (4 ft) long was filled with a homogenous mixture of propane and air at stoichiometric proportions. The pipe was rotated at constant speed about its center (like a propeller), and the mixture was ignited at one end by an electric spark. Ionization probes mounted at intervals along the pipe sensed the flame-front movement, and in some tests a pressure transducer mounted near the center of rotation was used to measure the presure in the pipe. The measured flame-propagation rate is plotted below as a function of centrifugal-field strength. The data can be expressed by the equation V=5.67(P)0.106(g)0.387. Pressure measurements made during the combustion process show that the bulk burning rate increases in a manner similar to the flame-propagation rate.