Experimental Investigation of pressure fluctuations in the near field of subsonic jets at different Mach and Reynolds numbers

2012 ◽  
Author(s):  
Silvano Grizzi ◽  
Alessandro Di Marco ◽  
Roberto Camussi
Keyword(s):  
Experimental Investigation ◽  
Near Field ◽  
Pressure Fluctuations ◽  
Reynolds Numbers ◽  
Mach And Reynolds Numbers

scholarly journals Numerical and Experimental Investigation of Phaseless Spherical Near-Field Antenna Measurements

2021 ◽  
pp. 1-1
Author(s):  
Fernando Rodriguez Varela ◽  
Javier Fernandez Alvarez ◽  
Belen Galocha Iraguen ◽  
Manuel Sierra Castaner ◽  
Olav Breinbjerg
Keyword(s):  
Experimental Investigation ◽  
Near Field ◽  
Antenna Measurements

Experimental Investigation of Effect of Tip Coolant Ejection on Internal Flow Characteristics Within a Realistic Blade Coolant Channel

2013 ◽  
Author(s):  
Jian Pu ◽  
Zhaoqing Ke ◽  
Jianhua Wang ◽  
Lei Wang ◽  
Hongde You
Keyword(s):  
Experimental Investigation ◽  
Reynolds Number ◽  
Pressure Drop ◽  
Turbine Blade ◽  
Flow Rate ◽  
Flow Characteristics ◽  
Reynolds Numbers ◽  
Flow Ratio ◽  
Lp Turbine ◽  
Mass Flow Ratio

This paper presents an experimental investigation on the characteristics of the fluid flow within an entire coolant channel of a low pressure (LP) turbine blade. The serpentine channel, which keeps realistic blade geometry, consists of three passes connected by a 180° sharp bend and a semi-round bend, 2 tip exits and 25 trailing edge exits. The mean velocity fields within several typical cross sections were captured using a particle image velocimetry (PIV) system. Pressure and flow rate at each exit were determined through the measurements of local static pressure and volume flow rate. To optimize the design of LP turbine blade coolant channels, the effect of tip ejection ratio (ER) from 180° sharp bend on the flow characteristics in the coolant channel were experimentally investigated at a series of inlet Reynolds numbers from 25,000 to 50,000. A complex flow pattern, which is different from the previous investigations conducted by a simplified square or rectangular two-pass U-channel, is exhibited from the PIV results. This experimental investigation indicated that: a) in the main flow direction, the regions of separation bubble and flow impingement increase in size with a decrease of the ER; b) the shape, intensity and position of the secondary vortices are changed by the ER; c) the mass flow ratio of each exit to inlet is not sensitive to the inlet Reynolds number; d) the increase of the ER reduces the mass flow ratio through each trailing edge exit to the extent of about 23–28% of the ER = 0 reference under the condition that the tip exit located at 180° bend is full open; e) the pressure drop through the entire coolant channel decreases with an increase in the ER and inlet Reynolds number, and a reduction about 35–40% of the non-dimensional pressure drop is observed at different inlet Reynolds numbers, under the condition that the tip exit located at 180° bend is full open.

Experimental Investigation of Subsonic Turbulent Flow Over Single and Double Backward Facing Steps

1962 ◽  
Vol 84 (3) ◽  
pp. 317-325 ◽  
Author(s):  
D. E. Abbott ◽  
S. J. Kline
Keyword(s):  
Experimental Investigation ◽  
Velocity Profile ◽  
Flow Pattern ◽  
Reynolds Numbers ◽  
Area Ratio ◽  
Single Step ◽  
Reattachment Length ◽  
Double Step ◽  
Wide Range ◽  
Geometric Variables

Results are presented for flow patterns over backward facing steps covering a wide range of geometric variables. Velocity profile measurements are given for both single and double steps. The stall region is shown to consist of a complex pattern involving three distinct regions. The double step contains an assymmetry for large expansions, but approaches the single-step configuration with symmetric stall regions for small values of area ratio. No effect on flow pattern or reattachment length is found for a wide range of Reynolds numbers and turbulence intensities, provided the flow is fully turbulent before the step.

An Experimental Investigation of Flow-Induced Cavity Resonance

2001 ◽  
Author(s):  
Paul J. Zoccola ◽  
Theodore M. Farabee
Keyword(s):  
Experimental Investigation ◽  
Energy Production ◽  
Pressure Fluctuations ◽  
Cavity Resonance ◽  
Cavity Pressure ◽  
Novel Technique ◽  
Cavity Opening ◽  
The Mean ◽  
Marine Applications ◽  
Opening Phase

Abstract Excitation of cavity resonance by flow over an aperture is often a source of unwanted noise in aerospace, automotive, and marine applications. An experimental investigation of this phenomenon was conducted. Detailed measurements of the cavity pressure and the velocity field in the opening were performed in a quiet flow facility. Spectral data on cavity pressure fluctuations obtained for a variety of configurations were analyzed over a range of speeds to determine the behavior of both sheartones and cavity tones during non-resonant and resonant conditions. The mean and fluctuating velocity profiles as well as the cross-spectral properties between the velocity components and cavity pressure were also obtained within the cavity opening. Phase between the velocity components and the pressure was used to calculate the streamwise convection velocities across the opening. A novel technique used to measure vorticity allowed calculation of the measured energy production in the opening. The data support the finding that the resonant and non-resonant conditions are distinguished by the behavior of the convection velocity and by the distribution of energy production in the flow field.

Sign in / Sign up

Export Citation Format

Share Document