A theoretical study of the problem of ignition of a cold combustible mixture by a hot projectile is performed by approximating, firstly, the flow over its surface to a laminar flow of the mixture over a hot plate, and, secondly, the flow in the wake of the projectile to a plane laminar mixing of the cold unreacted mixture with the hot combustion products. Unlike the earlier analyses consisting of successive approximations and/or series expansions, the non-similar boundary layer equations are directly integrated by following a suitable numerical scheme. A characteristic parameter of the problem—the distance at which ignition occurs, which is defined by the presence of a temperature maximum—is obtained for different values of quantities relating to the properties of propane-air mixture, and to the speed as well as the dimensions of the projectile.