0
Research Papers

Computational Fluid Dynamic Analysis of Eccentric Atomization Spray Cooling Nozzle Designs for Micromachining

[+] Author and Article Information
Andressa Lunardelli

School of Engineering,
University of St. Thomas,
2115 Summit Ave.,
Saint Paul, MN 55105
e-mail: luna7991@stthomas.edu

John E. Wentz

School of Engineering,
University of St. Thomas,
2115 Summit Ave.,
Saint Paul, MN 55105
e-mail: went2252@stthomas.edu

1Corresponding author.

Contributed by the Manufacturing Engineering of ASME for publication in the JOURNAL OF MICRO- AND NANO-MANUFACTURING. Manuscript received May 29, 2013; final manuscript received February 26, 2014; published online April 8, 2014. Assoc. Editor: Stefan Dimov.

J. Micro Nano-Manuf 2(2), 021003 (Apr 08, 2014) (10 pages) Paper No: JMNM-13-1032; doi: 10.1115/1.4027094 History: Received May 29, 2013; Revised February 26, 2014

A recent development in cooling and lubrication technology for micromachining processes is the use of atomized spray cooling systems. These systems have been shown to be more effective than traditional methods of cooling and lubrication for extending tool life in micromachining. Typical nozzle systems for atomization spray cooling incorporate the mixing of high-speed gas and an atomized fluid carried by a gas stream. In a two-phase atomization spray cooling system, the atomized fluid can easily access the tool–workpiece interface, removing heat through evaporation and lubricating the region by the spreading of oil micro-droplets. The success of the system is determined in a large part by the nozzle design, which determines the atomized droplet's behavior at the cutting zone. In this study, computational fluid dynamics are used to investigate the effect of nozzle design on droplet delivery to the tool. An eccentric-angle nozzle design is evaluated through droplet flow modeling. A design of simulations methodology is used to study the design parameters of initial droplet velocity, high-speed gas velocity, and the angle change between the two inlets. The system is modeled as a steady-state multiphase system without phase change, and droplet interaction with the continuous phase is dictated in the model by drag forces and fluid surface tension. The Lagrangian method, with a one-way coupling approach, is used to analyze droplet delivery at the cutting zone. Following a factorial experimental design, deionized water droplets and a semisynthetic cutting fluid are evaluated through model simulations. Statistical analysis of responses (droplet velocity at tool, spray thickness, and droplet density at tool) show that droplet velocity is crucial for the nozzle design and that modifying the studied parameters does not change droplet density in the cutting zone.

FIGURES IN THIS ARTICLE
<>
Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Schematic of a typical atomization-based cooling system with an eccentric nozzle

Grahic Jump Location
Fig. 2

Coaxial nozzle design [4]

Grahic Jump Location
Fig. 3

(A) Eccentric nozzle with θ = 100 deg and (B) setup of the eccentric nozzle and tool

Grahic Jump Location
Fig. 4

Simulation of a 100 deg eccentric nozzle with 12.35 m/s initial droplet velocity and 28.63 m/s as high-speed air velocity

Grahic Jump Location
Fig. 5

Experimental validation of simulation of a 100 deg eccentric nozzle

Grahic Jump Location
Fig. 6

Geometry and variables of an eccentric spray nozzle

Grahic Jump Location
Fig. 7

(a) The tool is shown in relation to the nozzle and the yz-plane at 25.4 mm from the origin. (b) Spray thickness is shown in relation to the the symmetric plane yz-plane.

Grahic Jump Location
Fig. 8

Test 1 at θ = 125 deg and v2 = 17 m/s (a) particle tracking velocity streamlines and (b) average volume fraction and spray thickness

Grahic Jump Location
Fig. 9

Test 2 at θ = 155 deg and v2 = 17 m/s (a) particle tracking velocity streamlines and (b) average volume fraction and spray thickness

Grahic Jump Location
Fig. 10

Test 3 at θ = 125 deg and v2 = 26 m/s (a) particle tracking velocity streamlines and (b) average volume fraction and spray thickness

Grahic Jump Location
Fig. 11

Test 4 at θ = 155 deg and v2 = 26 m/s (a) particle tracking velocity streamlines and (b) average volume fraction and spray thickness

Grahic Jump Location
Fig. 12

Low eccentricity (θ = 125 deg) velocity profiles on the xy-plane

Grahic Jump Location
Fig. 13

High eccentricity (θ = 155 deg) velocity profiles on the xy-plane

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In