scholarly journals An Experimental Study on the Jet Pressure Performance of Organ–Helmholtz (O-H), Self-Excited Oscillating Nozzles

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 367
Author(s):  
Xiaochuan Wang ◽  
Yueqin Li ◽  
Yi Hu ◽  
Xiaolong Ding ◽  
Meijing Xiang ◽  
...  
Keyword(s):  
Pressure Pulsation ◽  
Peak Pressure ◽  
Structural Parameters ◽  
Geometric Parameters ◽  
Experimental Results ◽  
Target Distance ◽  
Pulsation Amplitude ◽  
Excited Oscillation ◽  
Organ Pipe ◽  
Pump Pressure

To make a better application of the self-excited oscillation jet, a compound organ–Helmholtz oscillation nozzle (OH nozzle) was designed to generate better pulse effects in the present study. The effects of geometric parameters on pressure characteristics of self-excited oscillation jets were investigated experimentally. The geometric parameters of OH nozzles were determined based on the design principle of the organ-pipe and Helmholtz nozzles. Various types of OH nozzles were tested to obtain the relationship between oscillation pressure and geometric parameters. Experimental results showed that some structural parameters are sensitive to the pump pressure, while others are not. The optimum geometric optimum parameters were obtained based on experimental results. The peak pressure and pressure pulsation amplitude are closely related to the target distance. The peak pressure decreases sharply with target distance at first and decreases with a further increase of the target distance. The peak pressure becomes stable beyond a certain range of target distance. With the increase of the target distance, the pressure pulsation amplitude increases at first and then decreases. The optimum target distance was determined based on experimental results to achieve better pulsation performance and has a value of 20 mm in the present study.

Effect of bionic mantis shrimp groove volute on vortex pump pressure pulsation

2018 ◽  
Vol 25 (10) ◽  
pp. 2399-2409
Author(s):  
Yun-qing Gu ◽  
Wen-qi Zhang ◽  
Jie-gang Mou ◽  
Shui-hua Zheng ◽  
Pei-jian Zhou ◽  
...  
Keyword(s):  
Pressure Pulsation ◽  
Mantis Shrimp ◽  
Vortex Pump ◽  
Pump Pressure

scholarly journals Investigation of Sheet Metal Forming Using a Rapid Compression Machine

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3957 ◽  
Author(s):  
Sandeep P. Patil ◽  
Yann Fenard ◽  
Shridhar Bailkeri ◽  
Karl Alexander Heufer ◽  
Bernd Markert
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Peak Pressure ◽  
Experimental Results ◽  
Maximum Height ◽  
Outer Diameter ◽  
Rapid Compression Machine ◽  
Damage Initiation ◽  
Rapid Compression

The primary goal of this work is to understand the deformation behavior of an aluminum alloy (Al) workpiece by using a rapid compression machine (RCM). The primary novelty in this work is that this is the first study on sheet metal forming using RCM. Numerical simulation and experimental results are in excellent agreement, e.g., the dome-shape, the maximum height, the final outer diameter, and the thickness distribution of the deformed workpiece. We demonstrate that the maximum deformation height grows linearly with the peak pressure with an intercept tending to zero. The proposed linear relationship can be effectively used for designing new components for a specific application. Moreover, the proposed numerical model was competent in reproducing the experimental results of damage initiation and evolution in case of high peak pressure as well as the initial misalignment of the workpiece. The results of this investigation revealed that a rapid compression machine can be utilized efficiently for the controlled forming of complex shapes of metal sheets.

Dynamic Simulation of Large Flow Solenoid Valve

2016 ◽  
Author(s):  
Z. Liu ◽  
X. Han ◽  
Y. F. Liu
Keyword(s):  
Dynamic Model ◽  
Dynamic Simulation ◽  
Dynamic Characteristics ◽  
Nonlinear Dynamic ◽  
Structural Parameters ◽  
Solenoid Valve ◽  
Simulation Software ◽  
Experimental Results ◽  
Nonlinear Dynamic Model ◽  
Large Flow

A nonlinear dynamic model of a large flow solenoid is presented with the multi-physics dynamic simulation software called SimulationX. Validation is performed by comparing the experimental results with the simulated ones. The dynamic characteristics of the large flow solenoid valve are analyzed. Different structural parameters are modified in this research and the diameter of the orifice is proved to be one of the most important parameters which influences the pressure response most.

Effects of Trailing Edge Position of Splitter Blade on the Pressure Pulsation in a Low Specific Centrifugal Pump

2019 ◽  
Author(s):  
Jinfeng Zhang
Keyword(s):  
Velocity Distribution ◽  
Turbulence Intensity ◽  
Pressure Fluctuation ◽  
Relative Velocity ◽  
Pressure Pulsation ◽  
Suction Side ◽  
Maximum Pressure ◽  
Trailing Edge ◽  
Flow Rates ◽  
Pulsation Amplitude

Abstract A combination of experimental and numerical simulation was carried out to analyze influence of trailing edge position of splitter blade on the pressure fluctuation in low specific pumps with and without splitter blades under different flow rates. Performance experiments and PIV tests were performed to verify the results of numerical calculation. Several monitor points were placed in the calculation model pump to collect the pressure fluctuation signals, which were processed by Fast Fourier Transform to obtain the frequency results for further analysis. Besides, turbulence intensity and relative velocity distribution were also analyzed in regions of impeller and volute. The results showed that compared with prototype without splitter blade and the splitter blade schemes, when the trailing edge of splitter blade deviates to the suction side of main blade, the maximum pressure pulsation amplitudes are the lowest at different monitoring points of model pump. And the variation of pressure pulsation amplitude in this scheme is relatively stable with the change of flow rates compared with other schemes. Furthermore, the splitter blade scheme with an appropriate trailing edge position has the lowest average turbulence intensity and optimal relative velocity distribution in main flow passage component. Therefore, this paper proposes a reference scheme of the trailing edge position of the splitter blade to effectively decrease predominate pressure pulsation amplitude.

Experimental Investigations Upon Fatigue Life of Circular Contacts With Transversal Furrow

2005 ◽  
Author(s):  
Delia F. Cerlinca ◽  
Emanuel N. Diaconescu
Keyword(s):  
Fatigue Life ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Geometric Parameters ◽  
Rolling Contact ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Contact Fatigue Life

Rolling contact fatigue depends essentially on both surface and subsurface populations of defects. First, this paper describes experimental results obtained in rolling contact fatigue tests in the presence of a furrow oriented transversally to the race-way. Then an attempt to predict theoretically the effect of geometric parameters of the furrow upon contact fatigue life is described.

Numerical Simulation of Performance of Steam Ejector Influenced by the Distance between Nozzle Outlet and Mixing Chamber Inlet

2011 ◽  
Vol 299-300 ◽  
pp. 970-973
Author(s):  
Xiao Chun Dai ◽  
Guo Jin Liao
Keyword(s):  
Numerical Simulation ◽  
Geometric Parameters ◽  
Experimental Results ◽  
Nozzle Outlet ◽  
Entrainment Ratio ◽  
Optimum Range ◽  
Steam Ejector ◽  
Mixing Chamber ◽  
Throat Diameter

The performance of a steam ejector was simulated using FLUENT. The performance of steam ejector was studied by changing the distance between primary nozzle outlet and mixing chamber inlet (DPM) while operating pressures and other geometric parameters were not varied. The entrainment ratios of the steam ejector with different values of DPM were calculated. The optimum range of DPM was given, which is changed from 1.8 to 2 times of the throat diameter of hybrid diffuser pipe. The errors of the CFD results to the experimental results of the entrainment ratio are not more than 15%.

Heat Transfer Performance During Condensation Inside Spiralled Micro-Fin Tubes

2004 ◽  
Vol 126 (3) ◽  
pp. 321-328 ◽  
Author(s):  
Jean-Pierre M. Bukasa ◽  
Leon Liebenberg ◽  
Josua P. Meyer
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Performance ◽  
Geometric Parameters ◽  
Experimental Results ◽  
Outer Diameter ◽  
Transfer Performance ◽  
Fin Tube ◽  
R 134A ◽  
Fin Tubes ◽  
Spiral Angle

The effect of the spiral angle on the heat transfer performance in micro-fin tube condensers has not yet been clearly established because other geometric parameters affecting the heat transfer performance were simultaneously varied in previous studies. This paper reports on the influence of the spiral angle on the heat transfer during condensation inside spiralled micro-fin tubes having all other geometric parameters constant. Tests were conducted for condensation of R-22, R-134a, and R-407C inside a smooth (9.52 mm outer diameter) and three micro-fin tubes with approximately the same diameter, having spiral angles of 10 deg, 18 deg, and 37 deg, respectively. Experimental results indicated a heat transfer augmentation with spiral angle increase. A new semi-empirical predictive correlation was developed for practical design of spiralled micro-fin tubes. The proposed new correlation predicted the majority of experimental results of the present study within a deviation zone of ±20%.

Experimental Study on Dynamic Characteristics of Self-Excited Oscillation Pulsed Jet

2014 ◽  
Vol 937 ◽  
pp. 624-631 ◽  
Author(s):  
Chuan Lin Tang ◽  
Jie Pei ◽  
Dong Hu
Keyword(s):  
Dynamic Characteristics ◽  
Cavity Length ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Pulsed Jet ◽  
Jet Impact ◽  
Result Show ◽  
Excited Oscillation ◽  
Pump Pressure ◽  
Submerged Conditions

The dynamic characteristics of the self-excited oscillation pulsed jet is tested by using pulsed jet impact variable cross-section beam in submerged conditions and make comparison with continuous jet, analyzing the effects of operating parameters and nozzle structure parameters on the dynamic characteristics of the pulsed jet. The result show that the oscillating frequency of jet decreases with the increase of cavity length while increases with the increase of the pump pressure. The energy of pulsed jet has obvious change with different cavity length.

Simulation of Structural Parameters and Superconducting Transition Temperature of MgB2 under Pressure

2005 ◽  
Vol 475-479 ◽  
pp. 3319-3322
Author(s):  
Yang Shao ◽  
X. Zhang ◽  
Fu Ling Tang
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
Pressure Effect ◽  
Structural Parameters ◽  
Experimental Results ◽  
Bcs Theory ◽  
Superconducting Transition ◽  
Potential Parameters

We successfully developed the potential parameters for simulation of MgB2. With these potential parameters, we calculate the lattice parameters and volume variations with pressure up to 240GPa. All these results agree well with experimental data under 40GPa and provide reasonable tendencies from 40GPa to 240GPa. By employing the McMillan expression, it is found that the lattice stiffening dominants the behavior of Tc under pressure in the scope of BCS theory. Using our calculated Grüneisen parameter G g , the simulated pressure effect on Tc accords well with experimental results. Our result shows that the Tc of MgB2 can be destroyed by high pressure.

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