The change in those two parameters is caused by and is in dependent function of the inlet spectrum. There has been discussed a two-component flow of air and gas in ventilation devices. A two-velocity scheme of flow is used to realise the numerical method. An integral method of investigation is used, based on the conditions of conservation of mass contents, quantity of motion and kinetic energy. It's been accepted that quantity of motion and energy change in function of inlet action. | Vietnam Journal of Mechanics,. NCST of Vietnam Vol. 22, 2000, No 1 (29 - 38) NUMERICAL AND EXPERIMENTAL MODELING OF INTERACTION BETWEEN A TURBULENT JET FLOW AND AN INLET H . D. LIEN*, I. S. ANTONOV** * Agricultural University - Hanoi, Faculty of Mechanization 8 Electrification ** Technical University of Sofia, Bulgaria, Hydroaerodynamics Department ABSTRACT. In ventilation devices to get rid of harmful substances out of working places, we use sucking devices. The local sources of pollution are evacuated by them. A basic element when creating the model of sucking device is: the source of harmful substances is discussed as a rising convective flow, which is ejected out of sucking spectrum, created by a sucking apparatus. In the present work, the flow is a whole one with variable quantity of motion and kinetic energy along it's length. The change in those two parameters is caused by and is in dependent function of the inlet spectrum. There has been discussed a two-component flow of air and gas in ventilation devices . A two-velocity scheme of flow is used to realise the numerical method. An integral method of investigation is used, based on the conditions of conservation of mass contents, quantity of motion and kinetic energy. It's been accepted that quantity of motion and energy change in function of inlet action. A comparison of numerical results and natural experiment are made for two conditions : full suck and not full suck . Conclusion is that the present model is precise and can be unset for engineering calculations . Notation Q c - capacity in initial section Qi - capacity in inlet L - distance between outgoing section of jet and inlet r 0 - initial radius of jet r i - initial radius of inlet ug - velocity of air (carrier phase) Upa - initial velocity of admixture Ugo - initial velocity of air Ru - dynamic boundary layer Rp - diffusion boundary layer Pp - density of admixture up - velocity of admixture (smoke) maximum velocity of air maximum velocity .
