A Study on Phase Difference Between Pressure Drop and Flow Rate of Sine Fluctuation in Rectangular Channel

2012 ◽  
Author(s):  
Bao Zhou ◽  
Pu-zhen Gao ◽  
Si-chao Tan ◽  
Jing-da Tian
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Phase Difference ◽  
Flow Rate ◽  
Delay Time ◽  
Rectangular Channel ◽  
Mean Values ◽  
Rate Fluctuation ◽  
Measurement Delay ◽  
Pressure Transmitter

An experimental investigation on fluctuating turbulent flow with different amplitudes, frequencies and mean values of flow rate in a narrow rectangular channel was carried out to determine the phase difference so as to find out real corresponding relationship between pressure drop and flow rate. It is found that the measurement delay time difference between the flow meter and the differential pressure transmitter is not a constant but vary with the different flow rate fluctuation conditions. The phase difference was calculated by a function which is given in this paper and tested by the result of two kinds of nonlinear fit methods, whose results agree well.

Experimental Research on Pulsating Two-Phase Flow Pressure Drop Characteristics in Horizontal Rectangular Channel

2014 ◽  
Author(s):  
Siqi Zhang ◽  
Puzhen Gao
Keyword(s):  
Pressure Drop ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Two Phase Flow ◽  
Rectangular Channel ◽  
Phase Flow ◽  
Two Phase ◽  
Mean Values ◽  
Water Mass Flow Rate

In spite of most previous studies since 1970, the theory of pulsating pipe flows supported by experimental investigations has not yet completed in comparison with the well-defined theory of steady pipe flows. Therefore, it seems that there is much to be done about experimental research in this field. In order to determine the resistance characteristics of two-phase flow under pulsatile conditions, an experimental investigation on two-phase flow with periodically fluctuating flow rates in a narrow rectangular channel is carried out. A frequency inverter is used to obtain experimental conditions with different fluctuating frequencies, amplitudes and mean values of water mass flow rate. After obtaining experimental results, comparisons between experimental frictional pressure drop values and theoretical calculations have been done. Two-phase flow on pulsating conditions is far more complicated than that on steady conditions because pulsating flow is composed of two parts: a steady component and a superimposed periodical time varying component called oscillation. In this paper, the influence of different fluctuating frequencies, amplitudes and mean values of liquid and gas mass flow rate on two-phase flow pressure drop characteristics is also discussed. The results show that the total pressure drop and water mass flow rate change with the same fluctuating period except for a phase difference. The phase lag also changes with the fluctuating frequencies and amplitude. The accelerating pressure drop changes dramatically in a fluctuating period, especially at the end of acceleration. Also, the time when the acceleration pressure drop has its maximum value lags the time when the acceleration reaches its peak, mainly because of the inertial of the fluid.

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.

Performance of a High-Solidity Wells Turbine for an OWC Wave Power Plant

1996 ◽  
Vol 118 (4) ◽  
pp. 263-268 ◽  
Author(s):  
L. M. C. Gato ◽  
V. Warfield ◽  
A. Thakker
Keyword(s):  
Experimental Investigation ◽  
Power Plant ◽  
Pressure Drop ◽  
Flow Rate ◽  
Aerodynamic Performance ◽  
Wave Power ◽  
Wells Turbine ◽  
Guide Vanes ◽  
Turbine Efficiency ◽  
Pressure Distributions

The paper describes an experimental investigation, and presents the results of the aerodynamic performance of a high-solidity Wells turbine for a wave power plant. A monoplane turbine of 0.6 m rotor diameter with guide vanes was built and tested. The tests were conducted in unidirectional steady airflow. Measurements taken include flow rate, pressure drop, torque, and rotational speed, as well as velocity and pressure distributions. Experimental results show that the presence of guide vanes can provide a remarkable increase in turbine efficiency.

Uncertainty Analysis for the Measurement of Oil-Water Flow Parameters, Part II: Pressure Drop

2020 ◽  
Vol 15 (1) ◽  
pp. 1-7
Author(s):  
A. Abubakar
Keyword(s):  
Pressure Drop ◽  
Water Flow ◽  
Flow Rate ◽  
Tap Water ◽  
Standard Uncertainty ◽  
Water Volume ◽  
Water Mixture ◽  
Oil Water ◽  
Pressure Transmitter ◽  
Inclined Pipes

The need to ensure qualitative and reliable measurement of pressure drop of the oil-water flow cannot be over emphasized. In this regard, this study focused on the investigation of uncertainty in the measurement of pressure drop of oil-water flow in different acrylic pipe inclinations (0, +5ᴼ, +10ᴼ and -5ᴼ) and diameters (30.6-, 55.7- and 74.7-mm ID). The working fluids were tap water and mineral-based hydraulic oil (Shell Tellus S2 V 15), with medium viscosity and density of 24 cP and 872 kgm-3 respectively while the interfacial tension between the water and the oil was 12.9 mN/m at 25 ᴼC. The selected flow conditions were 0.5 and 1.0 m/s mixture velocities each at 0.1, 0.5 and 0.9 input water volume fractions. The repeatability, accuracy of the pressure transmitter, flow rate of the oil-water mixture and holdup (particularly for the inclined flow) were the sources of errors in the measurement of the pressure drop. The results showed that the average relative uncertainties in the pressure drop in 30.6-mm ID pipe were ±4.6 %, ±10.8 %, ±11.2 % and ±10.8 % in the 0ᴼ, +5ᴼ, +10ᴼ and -5ᴼ inclined flows respectively. Similarly, the average relative uncertainties in the pressure drop in the horizontal 55.7-mm and 74.7-mm ID pipes were ±5.7 % and ±7.5 % respectively. The largest contribution to the uncertainty in the pressure drop came from the flow rate and water holdup in the horizontal and inclined pipes respectively. The least contribution in both  horizontal and inclined pipes came from the accuracy of the pressure transmitter. Key words: Oil-water flow; Pressure drops; Standard uncertainty, Combined standard uncertainty; Expanded uncertainty

Experimental investigation on frictional pressure drop of water in vertical rectangular channel

2012 ◽  
Vol 250 ◽  
pp. 567-572 ◽  
Author(s):  
Sheng-Jie Qin ◽  
Bing-De Chen ◽  
Xiao Yan ◽  
Ze-Jun Xiao ◽  
Yan-Ping Huang
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Rectangular Channel ◽  
Frictional Pressure Drop

An Experimental Investigation of the Shell-Side Pressure Drop of Enlarged-Hole Whole-Rounded Baffle Heat Exchanger

2010 ◽  
Vol 160-162 ◽  
pp. 1622-1627 ◽  
Author(s):  
Hai Yang Sun ◽  
Cai Fu Qian
Keyword(s):  
Experimental Investigation ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Flow Characteristics ◽  
Shell Side ◽  
Pressure Drops ◽  
Side Pressure

In this paper, the flow characteristics of the whole-rounded enlarged-hole baffle heat exchangers are experimentally studied with the stress on the shell-side pressure drops. It is found that the shell-side pressure drops for the whole-rounded baffles with the enlarged holes are greatly decreased. Compared with the square layout, the enlarged-hole whole-rounded baffles in the case of triangle layout is even more effective in decreasing the pressure drop. The shell-side pressure drops for the heat exchangers with the enlarged-hole whole-rounded baffles are proportional to the square of the flow rate.

Experimental investigation of Pressure Drop/Flow Rate Relationship for Small Aperture Holes for High Viscosity Fluids

2012 ◽  
Author(s):  
Rachna Jain ◽  
Ted Alan Long ◽  
Jasper Lane Dickson ◽  
Scott V. Brown ◽  
Edmond Shtepani
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Flow Rate ◽  
High Viscosity ◽  
Small Aperture ◽  
Rate Relationship ◽  
Drop Flow
Sign in / Sign up

Export Citation Format

Share Document