tailieunhanh - One modification of k turbulent model of two phase flows

A modification of k-c turbulent model is described with application to the numerical investigation of two-phase turbulent jets. In difference of existed two-parameter models, new three-parameter modification have been suggested. In this case an additional equation for transportation of turbulent energy of admixture - kp is used together with equations of transportation of carrier- phase turbulent energy - kg and its dissipatiqn - c. | Vietnam Journal of Mechanics, NCNST of Vietnam T. XX, 1998, No 2 (37 - 45) ONE MOJ)IFICATION OF K-" TURBULENT MODEL OF TWO-PHASE FLOWS HOANG Due LIEN Agricultural University-Hanoi, Faculty of Mechanization & Electrification I. S. ANTONOV Technical University-Sofia, Bulgaria, Hydro-aerodynamics Dept NGUYEN THANH NAM Polytechnic University HCM City, Mechanical Engineering Dept ABSTRACT. A modification of k-c turbulent model is described with application to the numerical investigation of two-phase turbulent jets. In difference of existed two-parameter models, new three-parameter modification have been suggested. In this case an additional equation for transportation of turbulent energy of admixture - kp is used together with equations of transportation of carrier- phase turbulent energy - kg and its dissipatiqn - c. Additional dissipation terms in the above mentioned equations are defined in connection with a new examination of the between-phases interaction forces determining jet . Symbols Axial components of velocity Vi(i=p,g,o,m) - Radial components of velocity Wi(i=p,g,o,m) - Tangential components of velocity U,'c,·--p,g,o,m ) - Axial pulsative components of velocity V/(i=p,g,o,m) - Radial pulsative components of velocity WI(i=p,g,o,m) - Tangential pulsative components of velocity Xi(o,m) - Concentrates x, r, IJ - Coordinates of cylindrical coordinates system. ki(i=p,g) -Kinetic energy of the motion c - Dissipative velocity of the motion p, g, o, m - Symbols of admixture; gas; in the initial section; max. values Re, Sc- Reynold and Smidth numbers vi( i=p,g) - Turbulent viscosity R;- Richarson's number C R - Coefficient of aerodynamic resistance ai(i=k,w [exp (-B)_ 1 '\"' F/ .v'. = =Pg L w. P• f3rt p9 2 IZk v<- pw P 3 kp] [Wp k9 r + 0. 5aU9 ] ar () • General from of additional dissipated components e; in the equation for turbulent energy of admixture will have a from: () An additional dissipated component