Measurement of wall shear stress in physiological pulsatile flows by flush-mounted hot film anemometry

1988 ◽  
Vol 16 (2) ◽  
pp. 235-238
Author(s):  
Subhashis Nandy ◽  
Alex Yefim Bekker ◽  
Gregory Allen Winchell ◽  
John Francis O'Riordan
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Pulsatile Flows ◽  
Wall Shear ◽  
Hot Film ◽  
Hot Film Anemometry

Use of Hot-Film Anemometry for Wall Shear Stress Measurements in Unsteady Flows

2010 ◽  
Author(s):  
C. Ariyaratne ◽  
F. Wang ◽  
S. He ◽  
A. E. Vardy
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Unsteady Flows ◽  
Momentum Exchange ◽  
Reynolds Analogy ◽  
Initial Flow ◽  
Stress Measurements ◽  
Wall Shear ◽  
Hot Film ◽  
Hot Film Anemometry

Hot-wire and hot-film anemometry are widely used in steady flows for instantaneous velocity measurements, and their use has been extended to velocity and wall shear stress measurements in unsteady flows. The technique of hot-film anemometry relies on the Reynolds analogy which relates the diffusion of heat to the momentum exchange. The paper investigates the applicability of the analogy in linearly varying flows. The investigation is a combination of CFD analyses using the Transition SST model and experimental measurements. Results show that, in a linearly accelerating flow, while wall shear stress increases immediately upon the onset of acceleration, heat transfer indicates a relative lag in response. A quantitative analysis of the effects of flow parameters shows that the deviant behaviour is especially pronounced with increasing acceleration and/or reduced initial flow Reynolds number. The initial deviation can be predicted using a non-dimensional parameter based on turbulence timescales and acceleration rate, thereby providing a possible solution to correcting wall shear stress measurements using hot-film anemometry in fast accelerating flows.

Flush-Mounted Hot Film Anemometer Accuracy in Pulsatile Flow

1986 ◽  
Vol 108 (3) ◽  
pp. 228-231 ◽  
Author(s):  
S. Nandy ◽  
J. M. Tarbell
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Pulsatile Flow ◽  
Straight Tube ◽  
Average Deviation ◽  
Pulsatile Flows ◽  
Measured Flow ◽  
Wall Shear ◽  
Hot Film ◽  
Low Shear

The accuracy of a flush-mounted hot film anemometer probe for wall shear stress measurements in physiological pulsatile flows was evaluated in fully developed pulsatile flow in a rigid straight tube. Measured wall shear stress waveform based on steady flow anemometer probe calibrations were compared to theoretical wall shear stress waveforms based on well-established theory and measured flow rate waveforms. The measured and theoretical waveforms were in close agreement during systole (average deviation of 14 percent at peak systole). As expected, agreement was poor during diastole because of flow reversal and diminished frequency response at low shear rate.

215 Development of micro-fabricated hot-film sensor by MEMS and study on its validation of the wall shear stress fluctuation measurement

2014 ◽  
Vol 2014.63 (0) ◽  
pp. _215-1_-_215-2_
Author(s):  
Takuya SAWADA ◽  
Osamu TERASHIMA ◽  
Yasuhiko SAKAI ◽  
Kouji Nagata ◽  
Mitsuhiro SHIKIDA ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Film Sensor ◽  
Stress Fluctuation ◽  
Wall Shear ◽  
Hot Film ◽  
Fluctuation Measurement ◽  
Hot Film Sensor

Two-component hot-film probe for measurements of wall shear stress

1993 ◽  
Vol 15 (6) ◽  
pp. 380-384 ◽  
Author(s):  
B. M. Sumer ◽  
M. M. Arnskov ◽  
N. Christiansen ◽  
F. E. Jørgensen
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Two Component ◽  
Wall Shear ◽  
Hot Film

A Technique for the Measurement of Wall Shear Stress Based on Micro Fabricated Hot-Film Sensor

2013 ◽  
Author(s):  
Takuya Sawada ◽  
Osamu Terashima ◽  
Yasuhiko Sakai ◽  
Kouji Nagata ◽  
Mitsuhiro Shikida ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Turbulent Flows ◽  
Temporal Resolution ◽  
Large Scale ◽  
High Temporal Resolution ◽  
Film Sensor ◽  
Wall Shear ◽  
Hot Film ◽  
Hot Film Sensor

The objective of this study is to establish a technique for accurately measuring the wall shear stress in turbulent flows using a micro-fabricated hot-film sensor. Previously, we developed a hot-film sensor with a flexible polyimide-film substrate. This sensor can be attached to curved walls and be used in various situations. Furthermore, the sensor has a 20-μm-wide, heated thin metal film. However, the temporal resolution of this hot-film sensor is not very high owing to its substrate’s high heat capacity. Consequently, its performance is inadequate for measuring the wall shear stress “fluctuations” in turbulent flows. Therefore, we have developed another type of hot-film sensor in which the substrate is replaced with silicon, and a cavity has been introduced under the hot-film for reducing heat loss from the sensor and achieving high temporal resolution. Furthermore, for improving the sensor’s spatial resolution, the width of the hot-film is decreased to 10 μm. The structure of the hot-film’s pattern and the flow-detection mechanism are similar to those of the previous sensor. Experimental results show that new hot-film sensor works as expected and has better temporal resolution than the previous hot-film sensor. As future work, we will measure the wall shear stress for a turbulent wall-jet and discuss the relationship between a large-scale coherent vortex structure and wall shear stress based on data obtained using the new hot-film sensor.

scholarly journals On the measurement of wall shear stress with a patch-type micro-fabricated hot-film sensor

2014 ◽  
Vol 9 (3) ◽  
pp. JFST0029-JFST0029 ◽  
Author(s):  
Takuya SAWADA ◽  
Osamu TERASHIMA ◽  
Yasuhiko SAKAI ◽  
Kouji NAGATA ◽  
Mitsuhiro SHIKIDA ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Film Sensor ◽  
Patch Type ◽  
Wall Shear ◽  
Hot Film ◽  
Hot Film Sensor

0203 Measurement of wall shear stress with a micro hot film sensor

2015 ◽  
Vol 2015 (0) ◽  
pp. _0203-1_-_0203-2_
Author(s):  
Sora MURAMATSU ◽  
Koji IWANO ◽  
Yasuhiko SAKAI ◽  
Yasumasa ITO ◽  
Mitsuhiro SHIKIDA
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Film Sensor ◽  
Wall Shear ◽  
Hot Film ◽  
Hot Film Sensor
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