Energy Based Modeling of Ultra High-Pressure Waterjet Surface Preparation Processes

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
A. Chillman ◽  
M. Hashish ◽  
M. Ramulu
Keyword(s):  
High Pressure ◽  
Energy Density ◽  
Power Distribution ◽  
Experimental Studies ◽  
Surface Texturing ◽  
Surface Preparation ◽  
Orifice Diameter ◽  
Net Energy ◽  
Ultra High Pressure ◽  
Impulse Pressure

Ultra high-pressure waterjets (UHP-WJ) have been emerging as a viable method for surface texturing, cleaning, and peening of metallic materials. Previous experimental studies have suggested that removal of material can be related to the energy density of the waterjet impinging upon the workpiece, rather than the net energy. The net energy transferred to the workpiece is a function of four key process parameters, namely, (i) orifice diameter, (ii) orifice geometry, (iii) supply pressure, and (iv) traverse rate. The energy density also incorporates jet spreading as well as flow rate and impulse pressure distributions within the waterjet. In this paper, a novel representation of the power distribution within the waterjet is presented, as well as a relationship governing jet-material interaction. Empirical validation on a Ti-6Al-4V titanium alloy is presented, with good correlation noted between the predicted and experimental results.

A Novel Approach to Energy Based Evaluations of Ultra High-Pressure Waterjets

2010 ◽  
Author(s):  
A. Chillman ◽  
M. Hashish ◽  
M. Ramulu
Keyword(s):  
High Pressure ◽  
Energy Density ◽  
Power Distribution ◽  
Experimental Studies ◽  
Surface Texturing ◽  
Orifice Diameter ◽  
Net Energy ◽  
Ultra High Pressure ◽  
Novel Approach ◽  
Impulse Pressure

Ultra high-pressure waterjets (UHP-WJ) have been emerging as a viable method for surface texturing, cleaning, and peening of metallic materials. Previous experimental studies have suggested that removal of material can be related to the energy density of the waterjet impinging upon the workpiece, rather than the net energy. The net energy transferred to the workpiece is a function of four key process parameters, namely i.) orifice diameter, ii.) orifice geometry, iii.) supply pressure, and iv.) traverse rate. The energy density also incorporates jet spreading as well as flow rate and impulse pressure distributions within the waterjet. In this paper, a novel representation of the power distribution within the waterjet is presented, as well as a relationship governing jet-material interaction. Empirical validation on a Ti-6Al-4V titanium alloy is presented, with good correlation noted between the predicted and experimental results.

Waterjet Peening and Surface Preparation at 600MPa: A Preliminary Experimental Study

2006 ◽  
Vol 129 (4) ◽  
pp. 485-490 ◽  
Author(s):  
A. Chillman ◽  
M. Ramulu ◽  
M. Hashish
Keyword(s):  
Experimental Study ◽  
Plastic Deformation ◽  
High Pressure ◽  
Subsurface Layer ◽  
Surface Preparation ◽  
Material Surface ◽  
Ultra High Pressure ◽  
Shock Peening ◽  
Droplet Impacts ◽  
Compressive Residual Stresses

An experimental study was conducted to explore the surface preparation as well as the effects of high-pressure waterjet peening at 600MPa on the surface integrity and finish of metals. The concept of larger droplet size and multiple droplet impacts resulting from an ultra-high-pressure waterjet was used to explore and develop the peening process. A combination of microstructure analysis, microhardness measurements, and profilometry were used in determining the depth of plastic deformation and surface finish that result from the surface treatment process. It was found that waterjet peening at 600MPa induces plastic deformation to greater depths in the subsurface layer of metals than laser shock peening. The degree of plastic deformation and the state of the material surface were found to be strongly dependent on the peening conditions and desired surface roughness. Based on these first investigation results, water peening at 600MPa may serve as a new method for introducing compressive residual stresses in engineering components.

scholarly journals ESTIMATION OF NUCLEAR FUSION REQUIREMENTS IN BUBBLES DURING ULTRA-HIGH-PRESSURE, ULTRA-HIGH-TEMPERATURE CAVITATION PROMOTED BY MAGNETIC FIELD

2022 ◽  
Vol 5 (6) ◽  
pp. 102-115
Author(s):  
Toshihiko Yoshimura ◽  
Masataka Ijiri ◽  
Kazunori Sato
Keyword(s):  
Magnetic Field ◽  
High Pressure ◽  
High Temperature ◽  
Energy Density ◽  
Strong Magnetic Field ◽  
Threshold Value ◽  
Charged Species ◽  
Ultra High Pressure ◽  
Jet Nozzle ◽  
The Magnetic Field

In the present work, a strong magnetic field was applied near the outlet of the water jet nozzle to promote the generation of multifunction cavitation bubbles. Because these bubbles contained charged species, the bubbles experienced a Lorentz force due to the magnetic field and collided with greater force. As such, the internal bubble pressure exceeded the threshold value required for fusion to occur. The expansion of these charged bubbles in response to ultrasonic irradiation affected adjacent charged bubbles so that the energy density of the atoms in the bubbles was greater than the fusion threshold. The results of this work strongly suggest that the formation of bubbles via the UTPC process in conjunction with a strong magnetic field may result in bubble fusion.

scholarly journals Theoretical and Experimental Studies on Gadolinium at Ultra High Pressure.

1998 ◽  
Vol 7 ◽  
pp. 233-235 ◽  
Author(s):  
H. Hua ◽  
Y. K. Vohra ◽  
J. Akella ◽  
S. T. Weir ◽  
R. Ahujat ◽  
...  
Keyword(s):  
High Pressure ◽  
Experimental Studies ◽  
Ultra High Pressure

scholarly journals Optimal Planning and Operation of a Residential Energy Community under Shared Electricity Incentives

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2045
Author(s):  
Pierpaolo Garavaso ◽  
Fabio Bignucolo ◽  
Jacopo Vivian ◽  
Giulia Alessio ◽  
Michele De Carli
Keyword(s):  
Renewable Energy ◽  
Power Distribution ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Energy System ◽  
Distribution Networks ◽  
Building Envelope ◽  
Net Energy ◽  
Technical Equipment ◽  
Optimal Planning

Energy communities (ECs) are becoming increasingly common entities in power distribution networks. To promote local consumption of renewable energy sources, governments are supporting members of ECs with strong incentives on shared electricity. This policy encourages investments in the residential sector for building retrofit interventions and technical equipment renovations. In this paper, a general EC is modeled as an energy hub, which is deemed as a multi-energy system where different energy carriers are converted or stored to meet the building energy needs. Following the standardized matrix modeling approach, this paper introduces a novel methodology that aims at jointly identifying both optimal investments (planning) and optimal management strategies (operation) to supply the EC’s energy demand in the most convenient way under the current economic framework and policies. Optimal planning and operating results of five refurbishment cases for a real multi-family building are found and discussed, both in terms of overall cost and environmental impact. Simulation results verify that investing in building thermal efficiency leads to progressive electrification of end uses. It is demonstrated that the combination of improvements on building envelope thermal performances, photovoltaic (PV) generation, and heat pump results to be the most convenient refurbishment investment, allowing a 28% overall cost reduction compared to the benchmark scenario. Furthermore, incentives on shared electricity prove to stimulate higher renewable energy source (RES) penetration, reaching a significant reduction of emissions due to decreased net energy import.

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