NOTATION Z, r, ~, cylindrical coordinate system; Vz, Vr, ~ , components of the averaged velocity; v', pulsation component of the velocity in the direction of the averaged velocity vector; vo, average-flow-rate velocity of flow; H, radial gap of the annular channel; y, radial distance from the inner wall; b, width of mixing layer; m, degree of concurrent flow; S, stream swirling; ~, ~, coefficients of viscosity. Indices: O, average-flow-rate; I, inner; 2, outer stream; m, maximum; t, turbulent. LITERATURE CITED i. G.N. Abramovich et al., Turbulent Mixing of Gas Jets [in Russian], Nauka, Moscow(1974). 2. A.A. Sviridenkov and V. V. TretVyakov, "Experimental investigation of the mixing of turbulent, oppositely swirled jets in the initial section of an annular channel," Inzh.-Fiz. Zh., 4_~4, No. 2, 205-210 (1983). 3. G. N~ Abramovich, The Theory of Turbulent Jets [in Russian], Fizmatgiz, Moscow (1960). 4. V.V. Tret'yakov and V. I. Yagodkin, "A calculated investigation of turbulent swirled flow in a pipe," Inzh.-Fiz. Zh., 37, No. 2, 254-259 (1979). 5. I. Wygnanski and H. E. Fiedler, "~e two-dimensional mixing region," J. Fluid Mech., 41, Part 2, 327-361 (1970). 6. B.A. Zhestkov, Principles of the Theory and Calculation of the Thermal State of the Walls of Rocket Engine Combustion Chambers [in Russian], Ufim. Aviats. Inst., Ufa (1979).