Author: Randall S. Mainquist (1LT, USAF.)
Publisher:
ISBN:
Category : Holes
Languages : en
Pages : 170
Book Description
An Experimental Investigation Into the Suppression of Flow-induced Pressure Oscillations in Two-dimensional Open Cavities
Author: Randall S. Mainquist (1LT, USAF.)
Publisher:
ISBN:
Category : Holes
Languages : en
Pages : 170
Book Description
Publisher:
ISBN:
Category : Holes
Languages : en
Pages : 170
Book Description
Experimental Investigation to Suppress Flow-Induced Pressure Oscillations in Open Cavities
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 119
Book Description
High speed tangential flow over open cavities (e.g. aircraft weapon bays) can invoke large pressure oscillations within the cavity. These large oscillations can damage the cavity structure as well as items placed within the cavity. The purpose of this experimental study was to determine the effectiveness of suppressing pressure oscillations by manipulating the shear layer over a two-dimensional cavity with a length-to-depth ratio of two. Two methods, a frequency controllable control surface (fence) and pulsating secondary airflow at the cavity leading edge, were used to manipulate the shear layer. The suppression effectiveness of the fence utilized in both passive and active modes (zero to 120 Hz) was evaluated at six airflow Mach numbers (0.62, 0.76, 0.90, 1.07, 1.28, 1.53). The effectiveness of pulsating secondary airflow was evaluated at one airflow Mach number (1.28) and two flow injection angles (parallel and 45 degrees to the flow) at frequencies ranging from zero to 80 Hz. The effect of steady flow injection was also evaluated at mass flow rates per unit width ranging from 0.323 to 1.27 (lbm/sec/ft). Pressure recordings from within the cavity were made for each test. The effectiveness of a pulsating fence in suppressing the peak mode pressure oscillations proved to be less than that achievable with the fence static. The pulsed secondary flow injection technique was most effective when pulsed at a 45 degree angle to the external flow. Theses.
Publisher:
ISBN:
Category :
Languages : en
Pages : 119
Book Description
High speed tangential flow over open cavities (e.g. aircraft weapon bays) can invoke large pressure oscillations within the cavity. These large oscillations can damage the cavity structure as well as items placed within the cavity. The purpose of this experimental study was to determine the effectiveness of suppressing pressure oscillations by manipulating the shear layer over a two-dimensional cavity with a length-to-depth ratio of two. Two methods, a frequency controllable control surface (fence) and pulsating secondary airflow at the cavity leading edge, were used to manipulate the shear layer. The suppression effectiveness of the fence utilized in both passive and active modes (zero to 120 Hz) was evaluated at six airflow Mach numbers (0.62, 0.76, 0.90, 1.07, 1.28, 1.53). The effectiveness of pulsating secondary airflow was evaluated at one airflow Mach number (1.28) and two flow injection angles (parallel and 45 degrees to the flow) at frequencies ranging from zero to 80 Hz. The effect of steady flow injection was also evaluated at mass flow rates per unit width ranging from 0.323 to 1.27 (lbm/sec/ft). Pressure recordings from within the cavity were made for each test. The effectiveness of a pulsating fence in suppressing the peak mode pressure oscillations proved to be less than that achievable with the fence static. The pulsed secondary flow injection technique was most effective when pulsed at a 45 degree angle to the external flow. Theses.
Suppression of Flow-induced Pressure Oscillations in Cavities
Author: M. E. Franke
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
An Experimental Investigation of Pressure Oscillations in Two-dimensional Open Cavities
Author: Michael F. Marquardt (CAPT, USAF.)
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 110
Book Description
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 110
Book Description
Experimental Investigation of Flow-induced Cavity Resonance
Author: Paul Zoccola (Jr., J.)
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 200
Book Description
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 200
Book Description
An Experimental Investigation of Pressure Oscillations in Two- Dimensional Open Cavities
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 68
Book Description
An experimental study was conducted to determine the characteristics of the pressure oscillations in a small two-dimensional cavity exposed to tangential air flow. Various cavity configuration changes, involving the shape of the leading and trailing edge, were investigated to determine the relative capability to suppress the resonance in the cavity response. Five airflow Mach numbers (0.5, 0.6, 1.0, 1.3, 1.5) were used to investigate the Mach-response relationship. Two cavity lengths were considered (2 and 4 1/4 inches). The depth of the cavities was kept constant at one inch. Fluctuating pressure recordings and schlieren photographs were made of each test.
Publisher:
ISBN:
Category :
Languages : en
Pages : 68
Book Description
An experimental study was conducted to determine the characteristics of the pressure oscillations in a small two-dimensional cavity exposed to tangential air flow. Various cavity configuration changes, involving the shape of the leading and trailing edge, were investigated to determine the relative capability to suppress the resonance in the cavity response. Five airflow Mach numbers (0.5, 0.6, 1.0, 1.3, 1.5) were used to investigate the Mach-response relationship. Two cavity lengths were considered (2 and 4 1/4 inches). The depth of the cavities was kept constant at one inch. Fluctuating pressure recordings and schlieren photographs were made of each test.
Investigation for Suppressing Flow-induced Pressure Oscillations in an Open Cavity
Author: Fa-li Yang (CAPT, CAF.)
Publisher:
ISBN:
Category : Holes
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category : Holes
Languages : en
Pages :
Book Description
Suppression of Pressure Oscillations in Flow Past Resonant Cavities
Author: Stephen F. McGrath
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Suppression of Aerodynamically Induced Cavity Pressure Oscillations
Author: Leonard L. Shaw
Publisher:
ISBN:
Category : Oscillations
Languages : en
Pages : 68
Book Description
A flight test program was performed to gain further insight into the phenomenon of flow-induced cavity pressure oscillations and to evaluate the effectiveness of suppression concepts in eliminating or reducing the pressure oscillations. The cavities tested were rectangular with approximate dimensions of 17 inches long, 8.5 inches deep, and 8.75 inches wide and were instrumented with microphones, static pressure ports, and a thermocouple. The flight speeds ranged from Mach number 0.6 to 1.3 at pressure altitudes of 3,000, 20,000, and 30,000 feet. The suppression devices included leading edge spoilers and deflectors and trailing edge ramps and deflectors. Several combinations of these were tested. The results indicate that the flow-induced pressure oscillations in a cavity of the dimensions tested and for the speed range tested can be significantly reduced with leading edge spoilers in conjunction with a trailing edge ramp. Reductions as large as 30 dB were achieved for the predominant model frequency for a one-third octave band. Other combinations of the suppression devices afforded some reduction, but the spoiler ramp combination proved most effective. (Author).
Publisher:
ISBN:
Category : Oscillations
Languages : en
Pages : 68
Book Description
A flight test program was performed to gain further insight into the phenomenon of flow-induced cavity pressure oscillations and to evaluate the effectiveness of suppression concepts in eliminating or reducing the pressure oscillations. The cavities tested were rectangular with approximate dimensions of 17 inches long, 8.5 inches deep, and 8.75 inches wide and were instrumented with microphones, static pressure ports, and a thermocouple. The flight speeds ranged from Mach number 0.6 to 1.3 at pressure altitudes of 3,000, 20,000, and 30,000 feet. The suppression devices included leading edge spoilers and deflectors and trailing edge ramps and deflectors. Several combinations of these were tested. The results indicate that the flow-induced pressure oscillations in a cavity of the dimensions tested and for the speed range tested can be significantly reduced with leading edge spoilers in conjunction with a trailing edge ramp. Reductions as large as 30 dB were achieved for the predominant model frequency for a one-third octave band. Other combinations of the suppression devices afforded some reduction, but the spoiler ramp combination proved most effective. (Author).
An Experimental Investigation of Open Cavity Pressure Oscillations
Author: Dennis L. Carr
Publisher:
ISBN:
Category :
Languages : en
Pages : 74
Book Description
An experimental study was undertaken to investigate the use of a water table to define the parameters that influence the pressure oscillations resulting from air flow over open cavities. Tests were also conducted to investigate means to eliminate or reduce these oscillations. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 74
Book Description
An experimental study was undertaken to investigate the use of a water table to define the parameters that influence the pressure oscillations resulting from air flow over open cavities. Tests were also conducted to investigate means to eliminate or reduce these oscillations. (Author).