Echo-PIV Measurement Around the Pump System in the Nuclear Reactor

2011 ◽  
Author(s):  
Xin-Cheng Tu ◽  
Jae-Eun Cha ◽  
Hyoung-Bum Kim
Keyword(s):  
Flow Rate ◽  
Velocity Vector ◽  
Vector Fields ◽  
Nuclear Reactor ◽  
Velocity Fields ◽  
Fluid Machinery ◽  
Reactor Model ◽  
Pump System ◽  
Piv Measurement ◽  
Instantaneous Velocity Vector

Echo-PIV system was applied to measure the velocity fields of a pump system inside the nuclear reactor model. The scale-downed model of pump system driven by a motor was built for this study. 2D instantaneous velocity vector fields of the downstream region of impeller were obtained. The flow rate was calculated and compared with the result from the flow meter. From this study, the feasibility of echo-PIV for studying the opaque flow in the fluid machinery was shown.

scholarly journals Evolution of vortical structures behind an inclined flat plate

2018 ◽  
Vol 168 ◽  
pp. 05003 ◽  
Author(s):  
Pavel Procházka ◽  
Václav Uruba ◽  
Vladislav Skála
Keyword(s):  
Flat Plate ◽  
High Velocity ◽  
Velocity Vector ◽  
Vector Fields ◽  
Vortical Structures ◽  
Piv Technique ◽  
Streamwise Structures ◽  
New Hypothesis ◽  
Instantaneous Velocity Vector ◽  
Good Agreement

2D3C TR-PIV technique was utilized to investigate streamwise-oriented vortical structures behind an inclined flat plate. The angle of attack was set to 7 deg, several fields of view in the wake were investigated. The instantaneous velocity vector fields were captured, dynamics of the flow was studied using POD method. The streamwise structures are determined by vorticity and low- and high-velocity streaks are defined. The acquired results are in a good agreement with the new hypothesis of a principle of flight.

Aperture Effects in Planar Nearfield Acoustical Imaging

1988 ◽  
Vol 110 (1) ◽  
pp. 91-96 ◽  
Author(s):  
S. I. Hayek ◽  
T. W. Luce
Keyword(s):  
Velocity Vector ◽  
Vector Fields ◽  
Steel Plate ◽  
Velocity Fields ◽  
Aperture Size ◽  
Planar Surface ◽  
Acoustical Imaging ◽  
Set Of Points ◽  
Acoustical Holography ◽  
Nearfield Acoustical Holography

The influence of the size of the measurement aperture on the accuracy of reconstruction of the pressure and vector velocity fields using underwater nearfield acoustical holography technique is examined. In this measurement technique, the amplitude and phase of the pressure in the nearfield of a planar structure submerged in water is measured at a set of points on a planar surface which constitute the measurement aperture. The reconstruction of the pressure and velocity vector fields on the surface of a vibrating submerged steel plate was found to be insensitive to the aperture size down to the size of the structure. Examples of aperture sizes ranging from six (6) times down to 1/2 of the size vibrating steel plate are shown. Thus, the total length of time spent on measurements underwater can be drastically reduced.

The instantaneous velocity fields of coherent structures in coflowing jets and wakes

1980 ◽  
Vol 101 (2) ◽  
pp. 243-256 ◽  
Author(s):  
A. E. Perry ◽  
T. T. Lim ◽  
M. S. Chong
Keyword(s):  
Coherent Structures ◽  
Velocity Vector ◽  
Vector Fields ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Point Theory ◽  
Velocity Fields ◽  
Instantaneous Velocity ◽  
Qualitative Description ◽  
Three Dimensional Flow

The instantaneous velocity vector fields which surround the coherent structures of Perry & Lim (1978) in coflowing jets and wakes have been successfully measured and related to the smoke patterns for Reynolds numbers of order 1000. By the use of critical point theory, a qualitative description of the three-dimensional flow field can be made and is applied to the simplest structures which were classified by Perry & Lim. From these results, the convection of smoke and vorticity from the source and the entrainment properties of the structures are discussed.

Reconstructing Three-Dimensional Fluid Velocity Vector Fields from Acoustic Transmission Measurements

1977 ◽  
pp. 307-326 ◽  
Author(s):  
S. A. Johnson ◽  
J. F. Greenleaf ◽  
C. R. Hansen ◽  
W. F. Samayoa ◽  
M. Tanaka ◽  
...  
Keyword(s):  
Velocity Vector ◽  
Vector Fields ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Acoustic Transmission ◽  
Transmission Measurements

Spray Formation and Fuel Flow Rate at the Multi-Stage Injections Injected From the Swirl Nozzle

2003 ◽  
Author(s):  
Kokichi Sawada ◽  
Shinji Nakao ◽  
Tsuneaki Ishima ◽  
Tomio Obokata ◽  
Katsuyoshi Kawachi ◽  
...  
Keyword(s):  
Flow Rate ◽  
Gasoline Engine ◽  
Fuel Injection ◽  
Pressure Oscillation ◽  
Injection Rate ◽  
Fuel Flow Rate ◽  
Two Stage ◽  
Fuel Flow ◽  
Piv Measurement ◽  
Valve Opening

The structure, droplet characteristics and instantaneous fuel injection rate of two stage injection spray designed for direct injection gasoline engine were analyzed experimentally. A particle image velocimetry (PIV) to evaluate the instantaneous two-dimensional velocity field, a phase Doppler anemometer (PDA) and an instantaneous fuel flow rate meter based on a laser Doppler anemometer (LDA flow rate meter) were applied for the measurements. A swirl nozzle injector was used and injection conditions were 25 Hz of spray frequency, 2 ms and 1ms of the first and the second injection durations and 2.4, 3.3 and 9.1 ms of valve opening intervals. The initial jet of the second stage injection can overtook the main spray body of the first stage injection under the valve opening interval of 2.4 and 3.3 ms. The LDA flow rate meter made the injection rate measurement with sufficient accuracy in the two stage injection and showed the unstable second injection due to remaining pressure oscillation in the injection pipe. Both time averaged and time resolved PDA results were compared in the intermittent spray. The interaction between the first and the second sprays was also demonstrated in vector map obtained by the PIV measurement.

Numerical and experimental investigation on the air flow characteristics of heating, ventilation, and air-conditioning module for a small electric vehicle

2019 ◽  
Vol 234 (6) ◽  
pp. 1597-1609
Author(s):  
Kang Li ◽  
Hao Gao ◽  
Peng Jia ◽  
Lin Su ◽  
Yidong Fang ◽  
...  
Keyword(s):  
Heat Pump ◽  
Flow Rate ◽  
Air Conditioning ◽  
Air Flow ◽  
Flow Characteristics ◽  
Cold Climate ◽  
Airflow Rate ◽  
Positive Temperature ◽  
Air Flow Rate ◽  
Pump System

In electrical vehicles, replacing positive temperature coefficient heater as heat source with an air source heat pump could improve the driving range and decrease energy consumption in cold climate. Design of the heating, ventilation, and air-conditioning module for heat pump system has a significant influence on its performance in each working mode. A newly designed heat pump heating, ventilation, and air-conditioning module was introduced in this paper. The air flow characteristics of the heat pump heating, ventilation, and air-conditioning module in four working modes were analyzed, and the air flow rate and wind resistance were obtained by numerical simulation. Experiments were also conducted for validating its airflow rate in each working mode. Results of these experiments show that some unfavorable phenomena such as flow maldistribution and vortex inside the heat pump heating, ventilation, and air-conditioning module exist, which could lead to insufficient utilization of the heat exchange area of heat exchangers and the generation of aerodynamic noise. Furthermore, the air flow rate of the original heating, ventilation, and air-conditioning module was also measured for comparison, and the designed heat pump heating, ventilation, and air-conditioning module shows nearly 15–20% decrease in each working mode.

Experimental Study of the Characteristics of Gas Impinging Streams Using PIV Technique

2013 ◽  
Author(s):  
Wei Wei ◽  
ZhiYi Li ◽  
Fengxia Liu ◽  
Zhijun Liu
Keyword(s):  
Mass Transfer ◽  
Experimental Study ◽  
Flow Field ◽  
Flow Rate ◽  
Particle Image ◽  
Velocity Fields ◽  
Experimental Equipment ◽  
Piv Technique ◽  
Tracer Particles ◽  
Image Velocimetry

Impinging streams technology has been widely used in many applications in recent years because of its enhancement to the heat and mass transfer between phases. In this paper, in order to investigate the influences of the impinging distance and flow rate on the characters of the flow field, gas-gas impinging streams flow fields are tested experimentally and analyze qualitatively with particle image velocimetry (PIV). The experimental equipment consists of two opposite nozzles which are the same axis. A PIV system is used to measure the characters of the 2-D flow field between two opposite nozzles. The gas is delivered by a compressor through two opposite jets which could be seeded with oil droplets as tracer particles. The effects of the flow rate and impinging distance on the velocity fields of impinging zone are investigated in detail. As the flow rate increases from 0.2 m3/h to 0.8 m3/h, the width of impinging zone increases from 0.25 to 0.5. However, the range of impinging zone does not change significantly as the impinging distance increases from 61mm to 94mm. The results indicate that the PIV technique is an effective method to measure and analyze the characters of impinging streams.

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