An Experimental Study on the Effects of Concentration Gradient and Mean Velocity on the Liftoff Characteristics of the Triple Flame

2003 ◽  
Vol 27 (8) ◽  
pp. 1061-1070
Keyword(s):  
Experimental Study ◽  
Concentration Gradient ◽  
Mean Velocity

Film Cooling Jet Aerodynamics for a Pipe and a Converging Nozzle Injection Hole

2000 ◽  
Author(s):  
Jun Sasahara ◽  
Yukiko Suzuki ◽  
Shigeru Tanaka ◽  
Takaaki Shizawa ◽  
Shinji Honami
Keyword(s):  
Boundary Layer ◽  
Experimental Study ◽  
Kinetic Energy ◽  
Film Cooling ◽  
Flux Ratio ◽  
Hot Wire ◽  
Injection Hole ◽  
Primary Flow ◽  
Mean Velocity ◽  
Nozzle Injection

This paper presents the experimental study of film cooling jet aerodynamics for a pipe and a converging nozzle injection hole. The pipe jet has a fully developed velocity profile, and the nozzle jet has a top-hat one at the exit of the injection hole. The film cooling jet is injected into a turbulent boundary layer on a flat plate with 30° inclination angle. The mass flux ratio of the cooling jet to the primary flow is set at 0.8 and 1.2. Three components of mean velocity, vorticity and turbulent kinetic energy are measured using an X-array hot wire anemometer. The kidney vortex from the pipe jet is located closer to the wall than those from the nozzle jet. A tab is also installed at the exit of an injection hole to prevent the primary flow from convoluting. The effect of tab on the pipe jet is explicit.

An Experimental Study of Streamwise Vortices in a Compressor Cascade

1988 ◽  
Author(s):  
Chen Fang ◽  
Chen Mao-Zhang ◽  
Jiang Hao-Kang
Keyword(s):  
Experimental Study ◽  
Vortex Pair ◽  
Secondary Vortex ◽  
Streamwise Vortices ◽  
Reynolds Stresses ◽  
Compressor Cascade ◽  
Suction Surface ◽  
Mean Velocity ◽  
Passage Vortex ◽  
Corner Vortex

An experimental study on the production and development of streamwise vortices in a compressor cascade is reported. At four locations inside and one location outside the blade passage, the mean velocity components, three turbulent intensities and three Reynolds stresses were measured with a “x” hot wire probe. The results obtained describe the flow structure in the corner between the end-wall and blade suction surface in detail. Besides a passage vortex within the passage, there exist a shed corner vortex pair and a secondary vortex pair in the corner. The characteristics of two vortex pairs were different from that of the passage vortex. The mechanism causing the shed corner vortex pair and secondary vortex pair and the effect of these vortices on the cascade losses are discussed.

Experimental Study of Uniform-Shear Flow Past a Rotating Cylinder

1995 ◽  
Vol 117 (1) ◽  
pp. 62-67 ◽  
Author(s):  
Hyung Jin Sung ◽  
Chong Kuk Chun ◽  
Jae Min Hyun
Keyword(s):  
Experimental Study ◽  
Shear Flow ◽  
Measurement Data ◽  
Rotating Cylinder ◽  
Velocity Profiles ◽  
Doppler Velocity ◽  
Velocity Measurements ◽  
Mean Velocity ◽  
Uniform Shear ◽  
Uniform Shear Flow

An experimental study is made of two-dimensional uniform-shear flow (U = Uc + Gy) past a rotating cylinder of diameter D. A water-tunnel, equipped with a shear generator, was constructed. Laser-Doppler velocity measurements were undertaken to describe the wake characteristics. Data are compiled over the ranges of 600≤Re≤1,200, the shear parameter K[≡GD/Uc] up to 0.15, and the value of the cylinder rotation parameter α[≡ωD/2Uc], – 2.0≤α≤2.0. The power spectra of velocity measurements at downstream locations were analyzed to examine the vortex shedding patterns. In general, the dominant shedding frequency is shifted to a higher value as |α| and K increase. When |α| increases beyond a certain threshold value, the dominant frequency becomes less distinct. If |α| takes a value larger than around 1.5, the velocity field becomes randomized and diffuse, and the organized Karman vortex street activity weakens. The variations of the Strouhal number with K and α are described. The evolution of mean velocity profiles in the wake field is depicted. Characterizations of the velocity profiles, as K and α vary, are made based on the measurement data.

MHD flow in a rectangular duct with pairs of conducting and non-conducting walls in the presence of a non-uniform magnetic field

1980 ◽  
Vol 96 (2) ◽  
pp. 335-353 ◽  
Author(s):  
Richard J. Holroyd
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
Reynolds Number ◽  
Uniform Magnetic Field ◽  
Hartmann Number ◽  
Mhd Flow ◽  
Magnetic Reynolds Number ◽  
Rectangular Duct ◽  
Mean Velocity ◽  
Side Walls

A theoretical and experimental study has been carried out on the flow of a liquid metal along a straight rectangular duct, whose pairs of opposite walls are highly conducting and insulating, situated in a planar non-uniform magnetic field parallel to the conducting walls. Magnitudes of the flux density and mean velocity are taken to be such that the Hartmann numberMand interaction parameterNhave very large values and the magnetic Reynolds number is extremely small.The theory qualitatively predicts the integral features of the flow, namely the distributions along the duct of the potential difference between the conducting walls and the pressure. The experimental results indicate that the velocity profile is severely distorted by regions of non-uniform magnetic field with fluid moving towards the conducting walls; even though these walls are very good conductors the flow behaves more like that in a non-conducting duct than that predicted for a duct with perfectly conducting side walls.

scholarly journals Experimental study on the mean velocity profile in the high Reynolds number turbulent pipe flow

2015 ◽  
Vol 81 (826) ◽  
pp. 15-00091-15-00091 ◽  
Author(s):  
Yuki WADA ◽  
Noriyuki FURUICHII ◽  
Yoshiya TERAO ◽  
Yoshiyuki TSUJI
Keyword(s):  
Experimental Study ◽  
Reynolds Number ◽  
Velocity Profile ◽  
Pipe Flow ◽  
High Reynolds Number ◽  
Turbulent Pipe Flow ◽  
Mean Velocity ◽  
The Mean ◽  
High Reynolds

Experimental Study of Turbulent Flow Induced by Regular and Irregular Waves Above a Rock-Armored Slope

2014 ◽  
Author(s):  
Konstantina A. Galani ◽  
Giannis D. Dimou ◽  
Athanassios A. Dimas
Keyword(s):  
Experimental Study ◽  
Turbulent Flow ◽  
Velocity Profiles ◽  
Irregular Waves ◽  
Wave Crest ◽  
Regular Waves ◽  
Mean Velocity ◽  
Peak Period ◽  
Wave Trough ◽  
Wave Heights

The aim of the present work is the experimental study of the turbulent flow induced by waves above a physical model of a rock-armored slope of 1/3. The armor consisted of two layers of rocks with characteristic diameter D50 = 4.4cm. Measurements of the instantaneous velocity fields were conducted using an underwater planar PIV system. Four cases of incoming waves were tested, two cases of regular waves of 1st order Stokes theory with wave period of 1.134s and wave heights of 0.04m and 0.08m, respectively, and two cases of irregular waves, generated from a JONSWAP spectrum, with a peak period of 1.134s and significant wave heights of 0.04m and 0.08m, respectively. For the regular waves, the period-averaged velocity profiles show the existence of a strong undertow current heading towards deep water, while turbulence is not homogeneous with larger horizontal fluctuations. The phase-averaged horizontal velocity profiles present systematically larger values during wave trough passage than during wave crest passage. Furthermore, as the depth becomes smaller, the waveform loses its symmetry, with the wave trough becoming wider and the wave crest steeper. For the irregular waves, the mean velocity profiles show the existence of an undertow current weaker in magnitude than the one in the regular waves, while turbulence is still not homogeneous with larger horizontal fluctuations. For both wave cases, spanwise vorticity, which is generated at the rough surface of the rock-armored slope, is transported landward by the turbulent velocities.

Experimental Study of Reynolds Number Effects on Three-Dimensional Offset Jets

2014 ◽  
Author(s):  
Zacharie M. J. Durand ◽  
Shawn P. Clark ◽  
Mark F. Tachie ◽  
Jarrod Malenchak ◽  
Getnet Muluye
Keyword(s):  
Experimental Study ◽  
Reynolds Number ◽  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Reynolds Shear Stress ◽  
Three Dimensional ◽  
Shear Stresses ◽  
Mean Velocity ◽  
Flow Measurements ◽  
Reynolds Number Effects

The effect of Reynolds number on three-dimensional offset jets was investigated in this study. An acoustic Doppler velocimeter simultaneously measured all three components of velocity, U, V and W, and turbulence intensity, urms, vrms, and wrms, and all three Reynolds shear stresses, uv, uw, and vw. Turbulent kinetic energy, k, was calculated with all three values of turbulence intensities. Flow measurements were performed at Reynolds numbers of 34,000, 53,000 and 86,000. Results of this experimental study indicate the wall-normal location of maximum mean velocity and jet spread to be independent of Reynolds number. The effects on maximum mean velocity decay are reduced with increasing Reynolds number. Profiles of mean velocities, U, V and W, turbulence intensities, urms, vrms, and wrms, and turbulent kinetic energy, k, show independence of Reynolds number. Reynolds shear stress uv was independent of Reynolds number while the magnitude of uw was reduced at higher Reynolds number.

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