2-DIMENSIONAL PROCESSES OF THE UNBOUNDED UNSHOCKED COMPRESSION OF A GAS

The exact solution of the two-dimensional unsteady problem of the inte raction of two one-dimensional non-self-similar Riemann compression wa ves, each of which generates an unlimited local increase in the gas de nsity in the neighbourhood of a moving compressive piston, is construc ted. Solutions are obtained in which the adiabatic exponents and the a ngle at which the Riemann waves interact are specially arranged to be consistent. Both limited and unlimited energy expenditure on such comp ression is considered. In both cases a cumulative gas jet arises in th e region of Riemann wave interference, the extent to which the gasdyna mic quantities accumulate being the same as for unlimited self-similar two-dimensional compression of a gas prism. Thus it is shown that hig h local degrees of energy accumulation can be attained for a broad cla ss of laws of control by unshocked compression. A phenomenon of partia l gas collapse is observed. (C) 1998 Elsevier Science Ltd. All rights reserved.