Study of Non-Isoenergetic Turbulent Jet Mixing in a Constant Area Duct

Study of Non-Isoenergetic Turbulent Jet Mixing in a Constant Area Duct
Author: J. H. Blasenak
Publisher:
Total Pages: 38
Release: 1976
Genre:
ISBN:

A study of non-isoenergetic turbulent jet mixing between two streams has been conducted. Using a previously derived theoretical analysis for ducted mixing, an experimental investigation was performed to verify this theory and to determine the non-isoenergetic turbulent jet mixing characteristics in a constant area duct. Temperature profiles were measured at several axial locations in the duct for both a concentric and an eccentric configuration. It was determined that the oretical and experimental temperature profiles agreed fairly well for both cases, although the concentric case showed better agreement than the eccentric case. It was also determined that a new constant of turbulence in the initial region was needed for non-isoenergetic mixing, mixing is generally more rapid than the theory predicted, the initial temperature difference between the two streams did not have much effect on the rate of mixing and a higher area ratio produced better agreement between the theory and the experimental data. It was concluded that the theory was good for a fairly simplified analysis. (Author).

A Study of Non-isoenergetic Turbulent Jet Mixing Between Compressible Subsonic Streams in Axi-symmetric Constant Area Duct

A Study of Non-isoenergetic Turbulent Jet Mixing Between Compressible Subsonic Streams in Axi-symmetric Constant Area Duct
Author: K. K. Khanna
Publisher:
Total Pages: 59
Release: 1969
Genre: Aerodynamics
ISBN:

The problem of turbulent mixing between two compressible streams in a constant area duct is analyzed. The velocity and temperature profiles were worked in the main region of the mixing chamber for axi-symmetric case. Turbulent free jet experimental data is used, to obtain expressions for velocity and temperature as a function of the distance from the inlet to the mixing chamber. It is found that energy diffuses more rapidly than momentum for ducted mixing. The results of the theoretical analysis indicate increasing tendency towards segregation of the streams for decreasing initial velocity difference between the mixing streams. On the basis of the mixing chamber length required to achieve adequate degree of mixing, it is concluded that a corrugated rim primary nozzle is needed to accelerate the mixing rate by increasing the contact surface between the streams. (Author).

An Experimental Investigation of Ducted, Reactive, Turbulent Jet Mixing with Recirculation

An Experimental Investigation of Ducted, Reactive, Turbulent Jet Mixing with Recirculation
Author: D. E. Chriss
Publisher:
Total Pages: 52
Release: 1977
Genre: Gas flow
ISBN:

An experimental investigation of ducted, two stream, subsonic, reactive, turbulent jet mixing with recirculation was conducted. A primary jet of air at a mass flow rate of 0.075 lb/sec and velocity of 700 ft/sec was surrounded by an outer, low velocity, hydrogen stream. Data were obtained with hydrogen-air ratios of 0.143 and 0.107. The duct-to-inner nozzle diameter ratio was ten. Radial distributions of hydrogen mass fraction, mean axial velocity, turbulence intensity, and total pressure as well as axial distributions of wall hydrogen mass fraction and wall static pressure are presented for axial stations from one-half to five duct diameters from the nozzle exit plane. Comparison of the experimental data with calculations assuming frozen or equilibrium chemistry indicate that he measured velocity, pressure, and composition data are, in general, self-consistent. The maximum turbulent intensities which occurred in the center of the mixing layer and within the recirculation eddy were very high having values of 20 percent of the jet exit velocity. The velocity and composition field indicate that, while and mixing in the reactive flow field is slower than for the nonreactive case, the reaction had little effect on the size and location of the recirculation zone within the mixing duct.

An Experimental Investigation of Ducted, Reactive, Turbulent Jet Mixing with Recirculation

An Experimental Investigation of Ducted, Reactive, Turbulent Jet Mixing with Recirculation
Author:
Publisher:
Total Pages: 0
Release: 1977
Genre:
ISBN:

An experimental investigation of ducted, two stream, subsonic, reactive, turbulent jet mixing with recirculation was conducted. A primary jet of air at a mass flow rate of 0.075 lb/sec and velocity of 700 ft/sec was surrounded by an outer, low velocity, hydrogen stream. Data were obtained with hydrogen-air ratios of 0.143 and 0.107. The duct-to-inner nozzle diameter ratio was ten. Radial distributions of hydrogen mass fraction, mean axial velocity, turbulence intensity, and total pressure as well as axial distributions of wall hydrogen mass fraction and wall static pressure are presented for axial stations from one-half to five duct diameters from the nozzle exit plane. Comparison of the experimental data with calculations assuming frozen or equilibrium chemistry indicate that he measured velocity, pressure, and composition data are, in general, self-consistent. The maximum turbulent intensities which occurred in the center of the mixing layer and within the recirculation eddy were very high having values of 20 percent of the jet exit velocity. The velocity and composition field indicate that, while and mixing in the reactive flow field is slower than for the nonreactive case, the reaction had little effect on the size and location of the recirculation zone within the mixing duct.

An Investigation of Ducted, Two-stream, Variable-density, Turbulent Jet Mixing with Recirculation

An Investigation of Ducted, Two-stream, Variable-density, Turbulent Jet Mixing with Recirculation
Author: Roy J. Schulz
Publisher:
Total Pages: 92
Release: 1977
Genre: Jets
ISBN:

An investigation was conducted of two-stream, variable-density, turbulent jet mixing with recirculation confined within an axisymmetric duct that simulated a combustor configuration. The recirculating flow fields in the combustor simulator were the result of coaxial jet mixing between a central, primary air stream with a velocity of about 650 ft/sec and an annular secondary stream of hydrogen with velocities of 13, 23, or 48 ft/sec, depending on the desired test conditions. Experimental measurements are presented of radial distributions of time-averaged axial velocity and hydrogen mass fraction, axial distributions of time-averaged static pressure on the duct wall, axial velocity on the duct centerline, and hydrogen mass fraction on the duct wall and on the duct centerline. A theoretical study of the experimental flows was also conducted using a finite difference numerical solution technique for the calculation of viscous, recirculating flows. Comparison of theory and experiment shows that the predictive technique and the turbulence transport model require further development before accurate prediction of recirculating turbulent flows can be realized.

Theoretical and Experimental Jet Mixing of an Eccentric Primary Jet in a Constant Area Duct

Theoretical and Experimental Jet Mixing of an Eccentric Primary Jet in a Constant Area Duct
Author: W. Tabakoff
Publisher:
Total Pages: 52
Release: 1970
Genre:
ISBN:

The problem of turbulent mixing between two compressible streams in a constant duct area and with eccentric primary flow jet is analyzed. A theoretical analysis is presented for the velocity profiles. It was found that these profiles with or without eccentricity are almost the same if they are referred to the axis of the primary flow jet. An experimental investigation for the case of eccentricity ratio (e/R) equal to 0.25, given area ratios 3 and 7.16 and with a velocity ratio ranging from 1.2 to 2.9 was performed. The theoretical analysis shows good agreement with the experimental results, especially for cases with high area ratios and with low velocity magnitudes. (Author).