Finding Optimal Design for Water Jet Cooling by means of D. F. P. Method.

Metal machining is one of the fundamental manufacturing processes. The principal cost of shaping metal parts is generated both in the work involved in shearing metal from the original stock, at the area where the chips are formed, and also in the work required to overcome the high frictional forces that exist between the chip and rake face. Current techniques for the lubrication and cooling of this area are not very effective, resulting in a machining cost which is much higher than need be. A more efficient lubricooling effect can be achieved by the use of a high-pressure water jet directed into the tool/chip interface. The study of this idea was prompted by results achieved in the 1950’s, but now extended to much higher jet injection pressures (up to 280 MPa). The emphasis of this article is on the comparison of the coefficient of friction at the tool/rake interface for conventional and high-pressure jet cooling and also on reporting some practical results. Evaluation of these results indicates both a significant gain in the material removal rate as well as an improvement in the chip shape. The results are for a UNS 1020 steel—a representative of the poorly machinable materials.

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On the Application of Intrinsic Thermocouples in Temperature Measurements in Water Jet Cooling

Numerical Heat Transfer Part A Applications ◽

10.1080/10407780600829456 ◽

2007 ◽

Vol 51 (4) ◽

pp. 343-362 ◽

Cited By ~ 4

Author(s):

Fuchang Xu ◽

Mohamed S. Gadala

Keyword(s):

Water Jet ◽

Temperature Measurements ◽

Jet Cooling

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Prediction of Surface Temperature and Heat Flux of a Microelectronic Chip With Jet Impingement Cooling

Journal of Electronic Packaging ◽

10.1115/1.2904342 ◽

1990 ◽

Vol 112 (1) ◽

pp. 57-62 ◽

Cited By ~ 5

Author(s):

X. S. Wang ◽

Z. Dagan ◽

L. M. Jiji

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Surface Temperature ◽

Transfer Problem ◽

Jet Impingement ◽

Lower Surface ◽

Water Jet ◽

Uniform Heat Flux ◽

Impingement Cooling ◽

Jet Cooling

In this paper, a previously developed analytic solution is applied to the conjugate heat transfer problem of jet impingement cooling of a microelectronic chip. The analysis is used to predict the surface temperature and heat flux distributions of a chip cooled by a laminar impinging FC-77 liquid or water jet with uniform heat flux dissipation at the heated bottom of the chip. Results are presented for two jet diameters of 0.5 and 1 mm. It is shown that, for a constant Reynolds number, the surface temperature is lower when the jet diameter is smaller. On the other hand, when the jet diameter is increased, the surface temperature and heat flux distributions are more uniform. Water jet impingement cooling shows much lower surface temperature and much higher heat transfer coefficient than FC-77 jet cooling. The thermal resistance for FC-77 liquid jet is 6 times larger than that for a water jet.

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Molecular dynamics simulation study on ablation of silicon by water-jet-guided laser

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/0954408916662088 ◽

2016 ◽

Vol 231 (6) ◽

pp. 1217-1225 ◽

Cited By ~ 2

Author(s):

Weiguo Zhou ◽

Keyu Gong ◽

Jie Wan ◽

Lulu Quan ◽

Yuchuan Chu ◽

...

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Femtosecond Laser ◽

Water Jet ◽

Dynamics Simulation ◽

Jet Cooling ◽

Simulation Results ◽

Weber Potential ◽

Thermal Affected Zone

Stillinger–Weber potential and Z-layer energy model were adopted in molecular dynamics simulation to study the ablation of silicon by water-jet-guided femtosecond laser, and comparison was made by ablating silicon with or without water-jet cooling in our simulations. Simulation results indicated that with water-jet cooling, the thermal-affected zone could be reduced in area, and the peak of density could disappear more quickly. It was therefore concluded that water-jet-guided laser could be used to considerably improve the ablation quality of silicon.

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Effect of spray air settings of speed-increasing contra-angle handpieces on intrapulpal temperatures, drilling times, and coolant spray pattern

Clinical Oral Investigations ◽

10.1007/s00784-021-04030-3 ◽

2021 ◽

Author(s):

Edina Lempel ◽

József Szalma

Keyword(s):

Water Jet ◽

Drilling Force ◽

Cooling Mode ◽

Preparation Time ◽

Spray Pattern ◽

Jet Cooling ◽

Custom Made ◽

Molar Teeth ◽

Dental Practices ◽

Mist Cooling

Abstract Objectives Decreasing aerosol leaks are of great interest, especially in the recent era of COVID-19. The aim was to investigate intrapulpal heat development, coolant spray patterns, and the preparation efficiency of speed-increasing contra-angle handpieces with the spray air on (mist) or off (water jet) settings during restorative cavity preparations. Methods Standard-sized cavities were prepared in 80 extracted intact human molar teeth using diamond cylindrical drills with a 1:5 speed-increasing contra-angle handpiece. A custom-made device maintained the standardized lateral drilling force (3 N) and predetermined depth. Temperatures were measured using intrapulpal thermocouple probes. The four experimental groups were as follows: mist cooling mode at 15 mL/min (AIR15), water jet cooling mode at 15 mL/min (JET15), mist cooling mode at 30 mL/min (AIR30), and water jet cooling mode at 30 mL/min (JET30). The coolant spray pattern was captured using macro-photo imaging. Results The JET15 group had the highest increase in temperature (ΔT = 6.02 °C), while JET30 (ΔT = 2.24 °C; p < 0.001), AIR15 (ΔT = 3.34 °C; p = 0.042), and AIR30 (ΔT = 2.95 °C; p = 0.003) had significantly lower increases in temperature. Fine mist aerosol was formed in the AIR15 and AIR30 preparations but not in the JET15 and JET30 preparations (p < 0.001). The irrigation mode had no influence on the preparation time (p = 0.672). Conclusions Water jet irrigation using coolant at 30 mL/min appeared to be the optimal mode. Considering the safe intrapulpal temperatures and the absence of fine mist aerosols, this mode can be recommended for restorative cavity preparations. Clinical significance To increase infection control in dental practices, the water jet irrigation mode of speed-increasing handpieces with coolant flow rates of 30 mL/min should be considered for restorative cavity preparations.

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Analysis of Residual Stresses and Metallurgical Phase Changes in Centrifugally Cast Bi-Metal Grinding Rolls

Journal of Manufacturing Science and Engineering ◽

10.1115/1.2831106 ◽

1997 ◽

Vol 119 (3) ◽

pp. 290-297 ◽

Cited By ~ 1

Author(s):

Y. V. L. Narasimha Murthy ◽

G. Venkata Rao ◽

P. Krishna Iyer

Keyword(s):

Residual Stresses ◽

Phase Transformations ◽

Centrifugal Casting ◽

Water Jet ◽

Phase Changes ◽

Analysis Model ◽

Centrifugally Cast ◽

Jet Cooling ◽

Large Size ◽

Parametric Studies

A mathematical model was developed for computing the metallurgical phase transformations and residual stresses in centrifugal casting of bi-metal grinding rolls used for coal pulverizing. The model considers variation of thermo-mechanical properties of material with temperature, effects of phase changes and metallurgical phase transformations. Rolls idealized as having infinite cylindrical geometry and the actual finite conical geometry are analysed for cases of air and water jet cooling of the centrifuging die. As expected an increase in the martensitic fraction is obtained on the grinding surface due to water jet cooling. The study indicates that the large size rolls analysed herein have higher martensitic fraction as compared to small size roll. Simplified analysis model is developed for usage in parametric studies involving various sizes for initial sizing of the rolls.

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