Author: Shigeki Aoki
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Experimental Investigation of an Ejector Jet
Author: Shigeki Aoki
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Experimental Investigation of an Ejector-powered Free-jet Facility
Author: Mary Jo Long
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Experimental Investigation of a Thrust Augmenting Ejector
Author: Hidayat Wiradimadja
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
An ejector is basically a jet pump in which the kinetic energy of the jet is made to impart motion to the fluid surrounding it. During this process, in a well design system, the ejector as a whole experiences a thrust much higher than that of the jet alone. In principle, an ejector is nothing but a jet surrounded by a shroud. This investigation concerns the performance of a two- dimensional ejector with its primary jet excited by a novel method. A constant area duct was used in this experiment. The velocity of the jet at the exit was subsonic. Maximum thrust was obtained when the ejector to jet exit area ratio was about 35. Under this condition a thrust augmentation ratio of 1.65 was achieved, with the jet excited at 20 Hz, whereas without excitation it was only 1.40. The mixing characteristics of the jet under excitation was examined using flow visualization techniques. Smoke filaments illuminated by a sheet of powerful light and schlieren optics with the jet heated were used. Excitation of the jet was found to generate large vortex-like flow structures which might be responsible for enhanced mixing. These vortices extended to considerable distances on both sides of the jet.
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
An ejector is basically a jet pump in which the kinetic energy of the jet is made to impart motion to the fluid surrounding it. During this process, in a well design system, the ejector as a whole experiences a thrust much higher than that of the jet alone. In principle, an ejector is nothing but a jet surrounded by a shroud. This investigation concerns the performance of a two- dimensional ejector with its primary jet excited by a novel method. A constant area duct was used in this experiment. The velocity of the jet at the exit was subsonic. Maximum thrust was obtained when the ejector to jet exit area ratio was about 35. Under this condition a thrust augmentation ratio of 1.65 was achieved, with the jet excited at 20 Hz, whereas without excitation it was only 1.40. The mixing characteristics of the jet under excitation was examined using flow visualization techniques. Smoke filaments illuminated by a sheet of powerful light and schlieren optics with the jet heated were used. Excitation of the jet was found to generate large vortex-like flow structures which might be responsible for enhanced mixing. These vortices extended to considerable distances on both sides of the jet.
Experimental Investigation of a Triple-jet Gas Ejector
Author: Yu N. Vasilev
Publisher:
ISBN:
Category :
Languages : en
Pages : 19
Book Description
An experimental study was made of a three-jet gas ejector in an attempt to improve ejector efficiency. The three-jet ejector consists of a converging nozzle for the high pressure gas and an annular nozzle for the low-pressure gas, and is similar to a conventional ejector; it is, however, also equipped with a tube in the center of the converging nozzle through which part of the low-pressure gas is introduced. Plots were obtained for the dependence of the compression ratio on the pressure drop in the forechamber, at various positions of the central tube, and with the converging nozzles having diameter ratios of 0.55, 0.45, and 0.35. The results showed that a compression ratio of 31 and a pressure drop of 240 can be obtained in the three-jet ejector when the outlet of the central tube is located in the minimum pressure zone. This compares very favorably with the 5.6 and 42.5 values obtained in a conventional ejector. By using a start-up control in which the central tube outlet is gradually moved into the minimum pressure zone, a compression ratio of 44 and a pressure drop of 340 can be obtained. The overall results indicate that the operation of a conventional ejector can be substantially improved by installing a central tube for the low-pressure gas. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 19
Book Description
An experimental study was made of a three-jet gas ejector in an attempt to improve ejector efficiency. The three-jet ejector consists of a converging nozzle for the high pressure gas and an annular nozzle for the low-pressure gas, and is similar to a conventional ejector; it is, however, also equipped with a tube in the center of the converging nozzle through which part of the low-pressure gas is introduced. Plots were obtained for the dependence of the compression ratio on the pressure drop in the forechamber, at various positions of the central tube, and with the converging nozzles having diameter ratios of 0.55, 0.45, and 0.35. The results showed that a compression ratio of 31 and a pressure drop of 240 can be obtained in the three-jet ejector when the outlet of the central tube is located in the minimum pressure zone. This compares very favorably with the 5.6 and 42.5 values obtained in a conventional ejector. By using a start-up control in which the central tube outlet is gradually moved into the minimum pressure zone, a compression ratio of 44 and a pressure drop of 340 can be obtained. The overall results indicate that the operation of a conventional ejector can be substantially improved by installing a central tube for the low-pressure gas. (Author).
An Experimental Investigation of an Underexpanded Rectangular Jet Ejector
Author: Yeu-Chuan Hsia
Publisher:
ISBN:
Category : Air ducts
Languages : en
Pages : 216
Book Description
An experimental investigation was carried out on a rectangular ejector (constant area mixing duct) with an underexpanded rectangular jet as primary flow. This study investigated the mixing behavior of the ejector flow in general and attempted to identify the effects of the screech tones on the mixing and performance of the ejector. The quantities measured include frequency and amplitude of the screech tone, surface pressure on the ejector duct wall, and the mean flow velocity at the ejector exit in the two central planes of the primary jet. Schlieren flow visualization was made in the plane containing the short dimension of the primary nozzle. The screech tone frequency of the ejector depends not only on the primary jet pressure ratio but also on the ejector duct width. Variations of the screech tone frequency with both the pressure ratio and the duct width show staging behavior. For a given duct width, each screech tone stage matches with one of the transverse modes of the duct. The ejector performance, as determined from the static pressure distribution on the walls, shows irregular variation with pressure ratio, and is found to be related to the screech tone stages.
Publisher:
ISBN:
Category : Air ducts
Languages : en
Pages : 216
Book Description
An experimental investigation was carried out on a rectangular ejector (constant area mixing duct) with an underexpanded rectangular jet as primary flow. This study investigated the mixing behavior of the ejector flow in general and attempted to identify the effects of the screech tones on the mixing and performance of the ejector. The quantities measured include frequency and amplitude of the screech tone, surface pressure on the ejector duct wall, and the mean flow velocity at the ejector exit in the two central planes of the primary jet. Schlieren flow visualization was made in the plane containing the short dimension of the primary nozzle. The screech tone frequency of the ejector depends not only on the primary jet pressure ratio but also on the ejector duct width. Variations of the screech tone frequency with both the pressure ratio and the duct width show staging behavior. For a given duct width, each screech tone stage matches with one of the transverse modes of the duct. The ejector performance, as determined from the static pressure distribution on the walls, shows irregular variation with pressure ratio, and is found to be related to the screech tone stages.
Experimental Investigation of Effects of Primary Jet Flow Through a Zero-length Ejector on Base and Boattail Pressures of a Body of Revolution at Free-stream Mach Numbers of 1.62, 1.93, and 2.41
Author: Robert M. O'Donnell
Publisher:
ISBN:
Category :
Languages : en
Pages : 41
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 41
Book Description
Experimental Investigation of Thrust Augmenting Ejectors Using Vane Excited Primary Jets
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
An experimental investigation has been conducted to evaluate the entrainment characteristics of a thrust augmenting ejector, with a small, oscillating airfoil inserted in the potential core of the primary jet. Velocity distributions were measured across the width of the jet, at downstream distances of 20 and 40 nozzle widths, with the jet exhausting into still air and with the jet exhausting into an instrumented ejector shroud for the following range of parameters: Pressure ratio 1.137 and 1.268, amplitude of oscillation 2.6 deg and 6.9 deg zero-to-peak frequency of oscillation 0, 20, 40 and 60 Hz. Static pressure distributions were measured within the shroud when the jector was installed. The results amplify previously conducted studies. Jet spreading and entrainment appear to increase with increasing amplitude and frequency of oscillation and to decrease with increasing nozzle pressure ratio. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
An experimental investigation has been conducted to evaluate the entrainment characteristics of a thrust augmenting ejector, with a small, oscillating airfoil inserted in the potential core of the primary jet. Velocity distributions were measured across the width of the jet, at downstream distances of 20 and 40 nozzle widths, with the jet exhausting into still air and with the jet exhausting into an instrumented ejector shroud for the following range of parameters: Pressure ratio 1.137 and 1.268, amplitude of oscillation 2.6 deg and 6.9 deg zero-to-peak frequency of oscillation 0, 20, 40 and 60 Hz. Static pressure distributions were measured within the shroud when the jector was installed. The results amplify previously conducted studies. Jet spreading and entrainment appear to increase with increasing amplitude and frequency of oscillation and to decrease with increasing nozzle pressure ratio. (Author).
Experimental Investigation of Thrust Augmenting Ejectors Using Vane Excited Primary Jets
Author: Thomas Robert McClellan
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 143
Book Description
An experimental investigation has been conducted to evaluate the entrainment characteristics of a thrust augmenting ejector, with a small, oscillating airfoil inserted in the potential core of the primary jet. Velocity distributions were measured across the width of the jet, at downstream distances of 20 and 40 nozzle widths, with the jet exhausting into still air and with the jet exhausting into an instrumented ejector shroud for the following range of parameters: Pressure ratio 1.137 and 1.268, amplitude of oscillation 2.6 deg and 6.9 deg zero-to-peak frequency of oscillation 0, 20, 40 and 60 Hz. Static pressure distributions were measured within the shroud when the jector was installed. The results amplify previously conducted studies. Jet spreading and entrainment appear to increase with increasing amplitude and frequency of oscillation and to decrease with increasing nozzle pressure ratio. (Author).
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 143
Book Description
An experimental investigation has been conducted to evaluate the entrainment characteristics of a thrust augmenting ejector, with a small, oscillating airfoil inserted in the potential core of the primary jet. Velocity distributions were measured across the width of the jet, at downstream distances of 20 and 40 nozzle widths, with the jet exhausting into still air and with the jet exhausting into an instrumented ejector shroud for the following range of parameters: Pressure ratio 1.137 and 1.268, amplitude of oscillation 2.6 deg and 6.9 deg zero-to-peak frequency of oscillation 0, 20, 40 and 60 Hz. Static pressure distributions were measured within the shroud when the jector was installed. The results amplify previously conducted studies. Jet spreading and entrainment appear to increase with increasing amplitude and frequency of oscillation and to decrease with increasing nozzle pressure ratio. (Author).
Experimental Investigation of a Supersonic Air Air Ejector Operating with a Second Throat
Author: Sheridan D. Johnston
Publisher:
ISBN:
Category : Supersonic diffusers
Languages : en
Pages : 52
Book Description
Publisher:
ISBN:
Category : Supersonic diffusers
Languages : en
Pages : 52
Book Description
An Analytical and Experimental Investigation of an Unsteady Flow Ejector
Author: Khare, Jitendra Mai
Publisher: 1973.
ISBN:
Category : Jets
Languages : en
Pages : 202
Book Description
Publisher: 1973.
ISBN:
Category : Jets
Languages : en
Pages : 202
Book Description