Investigation of the pulsed waterjet flow field inside and outside of the nozzle excited by ultrasonic vibration

2018 ◽  
Vol 99 (1-4) ◽  
pp. 453-460 ◽  
Author(s):  
Rongguo Hou ◽  
Tao Wang ◽  
Zhe Lv ◽  
Yebing Tian
Keyword(s):  
Flow Field ◽  
Ultrasonic Vibration ◽  
Pulsed Waterjet

scholarly journals Research on Ultrasonic Vibration Assisted Electrical Discharge Machining SiCp/Al Composite

2021 ◽  
Author(s):  
Xiang Gao ◽  
Jucai Li ◽  
Qixuan Xing ◽  
Qinhe Zhang
Keyword(s):  
Surface Roughness ◽  
Flow Field ◽  
Ultrasonic Vibration ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Pulse Interval ◽  
Tool Electrode ◽  
Gap Flow ◽  
Al Composite

Abstract In this paper, ultrasonic-vibration assisted electrical discharge machining (UEDM) is used to process SiCp/Al composite materials in order to achieve a higher material removal rate (MRR) and lower surface roughness, width overcut, and relative tool wear rate (RTWR). FLUENT software was used to simulate the gap flow field. The simulation results of the gap flow field show that the ultrasonic vibration of the tool electrode is conducive to the removal of chips, which makes the discharge more stable and improves the machining efficiency. Based on the single factor experiment, the effects of peak current, reference voltage, pulse width, and pulse interval on MRR, surface roughness, width overcut, and RTWR of the workpiece are studied. Then, based on the orthogonal experiment, the grey relational analysis method was used to optimize the process parameters, and the order of the influence of the 4 process indicators on the comprehensive performance and the optimal processing parameter combination was obtained. The reliability of the process optimization was verified with experiments.

scholarly journals Simulation and Experimental Study on the Ultrasonic Micro-Vibration De-Icing Method for Wind Turbine Blades

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8246
Author(s):  
Yan Li ◽  
He Shen ◽  
Wenfeng Guo
Keyword(s):  
Power Generation ◽  
Flow Field ◽  
Wind Turbine ◽  
Ultrasonic Vibration ◽  
Wind Turbines ◽  
Adhesive Strength ◽  
Field Condition ◽  
Excitation Frequency ◽  
Return Flow ◽  
Micro Vibration

In cold and humid regions, ice accretion sometimes develops on the blades of wind turbines. Blade icing reduces the power generation of the wind turbine and affects the safe operation of the wind farm. For this paper, ultrasonic micro-vibration was researched as an effective de-icing method to remove ice from the wind turbine blade surface and improve the efficiency of wind turbine power generation. A blade segment with NACA0018 airfoil and the hollow structure at the leading edge was designed. The modal analysis of the blade was simulated by ANSYS, and the de-icing vibration mode was selected. Based on the simulation results, the blade segment sample with PZT patches was machined, and its natural frequencies were measured with an impedance analyzer. A return-flow icing wind tunnel system, and a device used to measure the adhesive strength of ice covering the airfoil blade, were designed and manufactured. The experiments on the adhesive strength of the ice were carried out under the excitation of the ultrasonic vibration. The experimental results show that the adhesive strength of the ice, which was generated under the dynamic flow field condition, was lower than the ice generated by water under the static flow field condition. Under the excitation of the ultrasonic vibration, the adhesive strength of the ice decreased. When the excitation frequency was 21.228 kHz, the adhesive strength was the lowest, which was 0.084 MPa. These research findings lay the theoretical and experimental foundations for researching in-depth the application of the ultrasonic de-icing technology to wind turbines.

Numerical Study of the Combined Free-Forced Convection and Mass Transfer Flow Past a Vertical Porous Plate in a Porous Medium with Heat Generation and Thermal Diffusion

2006 ◽  
Vol 11 (4) ◽  
pp. 331-343 ◽  
Author(s):  
M. S. Alam ◽  
M. M. Rahman ◽  
M. A. Samad
Keyword(s):  
Mass Transfer ◽  
Flow Field ◽  
Differential Equations ◽  
Forced Convection ◽  
Heat Generation ◽  
Numerical Study ◽  
Porous Plate ◽  
Integration Scheme ◽  
Suction Parameter ◽  
Transfer Flow

The problem of combined free-forced convection and mass transfer flow over a vertical porous flat plate, in presence of heat generation and thermaldiffusion, is studied numerically. The non-linear partial differential equations and their boundary conditions, describing the problem under consideration, are transformed into a system of ordinary differential equations by using usual similarity transformations. This system is solved numerically by applying Nachtsheim-Swigert shooting iteration technique together with Runge-Kutta sixth order integration scheme. The effects of suction parameter, heat generation parameter and Soret number are examined on the flow field of a hydrogen-air mixture as a non-chemical reacting fluid pair. The analysis of the obtained results showed that the flow field is significantly influenced by these parameters.

ATOMIZATION CHARACTERISTICS OF LIQUID JETS INJECTED INTO A HIGH-VELOCITY FLOW FIELD

1994 ◽  
Vol 4 (4) ◽  
pp. 451-471 ◽  
Author(s):  
Nobuyuki Yatsuyanagi ◽  
Hiroshi Sakamoto ◽  
Kazuo Sato
Keyword(s):  
Flow Field ◽  
High Velocity ◽  
Liquid Jets ◽  
High Velocity Flow ◽  
Velocity Flow ◽  
Atomization Characteristics
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