scholarly journals A proposal for the surface roughness wake field measurement at the TESLA Test Facility

1999 ◽  
Author(s):  
A. Novokhatski ◽  
M. Timm ◽  
T. Weiland ◽  
H. Schlarb
Keyword(s):  
Surface Roughness ◽  
Field Measurement ◽  
Test Facility ◽  
Wake Field

Investigation of Loss Impact From Production-Like Features in a Compressor Duct Under Engine Realistic Conditions

2017 ◽  
Author(s):  
Fredrik Wallin ◽  
Mark H. Ross ◽  
Max Rusche ◽  
Scott Morris ◽  
Steven Ray
Keyword(s):  
Surface Roughness ◽  
Total Pressure ◽  
Experimental Testing ◽  
Computational Grid ◽  
Test Facility ◽  
Pressure Probe ◽  
Cfd Analysis ◽  
Roughness Model ◽  
Geometrical Features ◽  
Real Geometry

An experimental and numerical investigation of the flow in a compressor duct with engine-realistic in-production features is presented in this paper. The experimental testing was conducted in the ND-FSCC test facility at University of Notre Dame, Indiana, USA. A baseline duct was also tested for back-to-back comparison. The ducts were heavily instrumented; duct inlet and exit flowfields were scanned using a five-hole pressure probe that provided total pressure, velocities and flow angles. Based on the five-hole probe total pressures, duct losses could be assessed. Furthermore the duct inlet boundary layers were traversed and turbulence intensity levels were assessed. For the CFD analysis of the production-like duct, a highly complex computational grid, resolving all the geometrical features present, was used. A previously validated surface roughness model was used to account for the cast aero-surfaces. Both experimental and numerical results show that there is a significant increase in loss for the production-like duct when compared to the baseline duct loss. The CFD results agree very well with experimental results for the baseline duct, which makes it possible to use the experimental data recorded for the production-like duct to validate CFD tools for real geometry effects, such as interface steps and surface roughness for example.

Electromagnetic wake-field due to surface roughness in an optical structure

2004 ◽  
Vol 95 (8) ◽  
pp. 4415-4426 ◽  
Author(s):  
S. Banna ◽  
D. Schieber ◽  
L. Schächter
Keyword(s):  
Surface Roughness ◽  
Wake Field ◽  
Optical Structure

Surface-Roughness Wakefield Measurements at Brookhaven Accelerator Test Facility

2002 ◽  
Vol 89 (17) ◽  
Author(s):  
F. Zhou ◽  
J. H. Wu ◽  
M. Babzien ◽  
I. Ben-Zvi ◽  
R. Malone ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Test Facility

Characteristics of the Mean Wind Speed Based on Field Measurement at Aizhai Bridge Gorge

2014 ◽  
Vol 521 ◽  
pp. 113-116
Author(s):  
Hong Xin Sun ◽  
Tao Yu ◽  
Xiu Yong Wang
Keyword(s):  
Surface Roughness ◽  
Wind Speed ◽  
Field Measurement ◽  
Bridge Site ◽  
Design Code ◽  
Average Wind Speed ◽  
Average Wind ◽  
Mean Wind Speed ◽  
The Mean ◽  
Fluctuating Wind

It is seriously different about characteristics of the mean wind speed between a deep gorge and plains, because of the deck of Aizhai bride to deep gorge bottom up to 335m. Characteristics of the mean wind speed in the deep gorge at the Aizhai bridge site are investigated based on field measurement using three 2D anemometers. The plan of field measurement was induced, and the wind speed, fluctuating wind speed and the 10min average wind speed with 10 days as a unit was analyzed. It if found that wind direction is basically consistent with the gorge toward. Based on the Wind-Resistant Design code, the surface roughness coefficients was fitted about 0.29, and very close to D class of the wind code.

scholarly journals Physical Modeling of Untrenched Pipeline Breakout From Sand-Bed in Ocean Currents

2010 ◽  
Author(s):  
Shu-Ming Yan ◽  
Fu-Ping Gao ◽  
Jing Cao ◽  
En-Yong Zhang ◽  
Guo-Hui Li ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Physical Modeling ◽  
Resistance Coefficient ◽  
Ocean Currents ◽  
Test Facility ◽  
Sand Particle ◽  
Lateral Stability ◽  
Soil Resistance ◽  
Pipe Surface ◽  
Flume Tests

The ultimate lateral soil resistance for pipe losing lateral stability on a sandy seabed under the action of ocean currents is investigated with a newly developed test facility by employing mechanical actuators to simulate hydrodynamic loads on the pipe. Two kinds of constraint conditions, i.e. anti-rolling pipe and freely-laid pipe, are taken into account, respectively. The experimental observations indicate that, the horizontal lateral soil resistance increases gradually to its maximum (ultimate) value when the additional settlement is fully developed. The buildup of the ultimate lateral soil resistance to the anti-rolling pipe benefits from not only the additional settlements but also the sand-particle collections in front of the moving pipe, especially for the anti-rolling pipes. The lateral-soil-resistance coefficient for the anti-rolling pipe is much larger than that for the freely-laid pipe. The pipe surface roughness also affects the lateral stability of anti-rolling pipes. A comparison is made between present mechanical-actuator tests and the previous water-flume tests, indicating the results of two types of tests are comparable and the local scour may reduce the pipe lateral stability in ocean currents.

Large Scale Leach Testing of Dwpf Canister Sections

1986 ◽  
Vol 84 ◽  
Author(s):  
Dennis F. Bickford ◽  
Daniel J. Pellarin
Keyword(s):  
Surface Roughness ◽  
Large Scale ◽  
Scale Up ◽  
Test Method ◽  
Waste Form ◽  
Test Facility ◽  
Small Scale ◽  
Glass Product ◽  
Leach Test ◽  
Sampling Statistics

AbstractA Large-Scale Leach Test Facility (LSLTF) has been constructed at the U.S. Department of Energy's Savannah River Laboratory (SRL) to perform static leach tests on 24-inch (610 mm)-diameter canister sections cut from simulated (nonradioactive) waste forms cast under reference conditions. The equipment and test procedures are designed to closely correspond to MCC-l leach test criteria.Less than a factor of 3 increase in leachability results from combined scale-up, glass-cracking, leached surface area estimation, and surface roughness effects. This factor is dominated by surface roughness of saw cut surfaces. The factor is negligible when compared to the 200,000/1 ratio of glass sample masses.The MCC-l, and other small-scale leach tests have been valuable in determining the relative merits of alternative waste form compositions. However, the actual waste glass to be stored in repositories is subject to fracture, devitrification, and container/glass interactions, which are difficult to simulate on a laboratory scale. Large-scale leach tests integrate these and other possible waste form characteristics that are not represented in typical small samples.The facility, equipment, test method and results of one year leach test- ing are discussed. These results substantiate the applicability of small scale test data which precede this work, and the use of small scale tests to simulate leaching of the Defense Waste Processing Facility's borosilicate glass product. Exceptionally good sampling statistics make the large scale data particularly well suited for verification of models of leachability rates.

Effect of Surface Roughness on Loss Behaviour, Aerodynamic Loading and Boundary Layer Development of a Low-Pressure Gas Turbine Airfoil

2010 ◽  
Author(s):  
Marco Montis ◽  
Reinhard Niehuis ◽  
Andreas Fiala
Keyword(s):  
Boundary Layer ◽  
Surface Roughness ◽  
Low Pressure ◽  
Test Facility ◽  
Hot Wire ◽  
Wire Probe ◽  
Aerodynamic Loading ◽  
Boundary Layer Development ◽  
Layer Development ◽  
Effect Of Surface

Aerodynamic measurements on the linear low-pressure turbine cascade T106C were conducted in a high speed test facility, in order to investigate the effect of surface roughness on loss behaviour, aerodynamic loading, and boundary layer development. Three different roughnesses were investigated, with a ratio of the center line average roughness to the profile chord of 0.8·10−5, 5·10−5 and 25·10−5. Tests were carried out under design outlet Mach number (Ma2th = 0.6), outlet Reynolds number ranging from Re2th = 5·104 to Re2th = 7·105 and inlet turbulence level Tu1 = 3% and Tu1 = 6%. The flow field downstream of the cascade and the loading distribution on the profiles were measured for each investigated operating point using five hole probes and surface static pressure taps. Additional measurements with a hot-wire probe in the suction surface (SS) boundary layer were also conducted, in order to investigate the differences in boundary layer development due to surface roughness. From loss and blade loading measurements it was found that roughness has no influence on the pressure distribution on the profile, although the highest investigated roughness produces a significant loss reduction at low Reynolds numbers. Hot-wire probe surveys show that at Re2th = 9·104 the boundary layer for the highest roughness immediately upstream of the flow separation point on the SS is substantially thinner than for the middle roughness and the smooth profile.

Rough Surface Effects on Film Cooling of the Suction Side Surface of a Turbine Vane

2003 ◽  
Author(s):  
David G. Bogard ◽  
Daniel Snook ◽  
Atul Kohli
Keyword(s):  
Surface Roughness ◽  
Film Cooling ◽  
Surface Wind ◽  
Density Ratio ◽  
Leading Edge ◽  
Test Facility ◽  
Roughness Effects ◽  
Cooling Performance ◽  
Coolant Injection ◽  
Adiabatic Effectiveness

In-service turbine airfoils generally have surface roughness much greater than new airfoils due to deposition, erosion, and spallation. This surface roughness has the effects of promoting early transition and increasing surface friction and heat transfer rates. When film cooling is used on the airfoil, the surface roughness affects film cooling performance by changing the approach boundary layer flow, and by increasing the turbulent mixing downstream of coolant injection. Previous studies of surface roughness effects on film cooling performance have used flat surface wind tunnel facilities. The present study was unique in using a simulated vane test facility. Hence it is the first study of surface roughness effects on film cooling of a highly curved surface. In our experiments, effects of roughness upstream and downstream of coolant injection were studied. Combined effects of leading edge showerhead injection and high mainstream turbulence levels were also investigated. In this study, determination of the effects on film cooling performance was limited to measurements of adiabatic effectiveness. Each configuration was tested over a range of blowing ratios and with a density ratio of 1.6. In each case roughness caused a significant degradation in adiabatic effectiveness. Roughness was observed to have a much greater effect on adiabatic effectiveness on the vane geometry than previous studies had observed using flat surfaces.

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