Abstract

An ongoing research effort has been conducted for years to investigate the feasibility of mixing the air with mist (micron-level water droplets) to enhance heat transfer. It becomes very interesting to investigate how these tiny droplets behave in conjunction with the periodic sweeping jets. Will they move synchronously with the fluid or asynchronously with a phase lag? How would the interaction between the droplets and the sweeping jets affect the film cooling effectiveness? To answer these questions, Part II of this paper specifically focuses on investigating the droplet dynamics and thermoflow behavior of droplet evaporation on film cooling effectiveness in a sweeping jet. An unsteady Reynolds Averaged Navier–Stokes simulation accompanied by the k–ω shear stress transport turbulence model is used in this study. The multiphase computational fluid dynamics model employs an Eulerian–Lagrangian approach. The Eulerian method is used for the continuous phase including air and water vapor and the Lagrangian method in terms of the discrete phase model is used to simulate the dispersed phase (e.g., liquid droplets) in a continuous phase (e.g., air). A mist ratio of 10% with a droplet size of 10 μm was used in this study. The results show that, for a blowing ratio of 1, using mist provides better film cooling performance with an average enhancement of 50–90% in comparison to that without mist. Using a mist ratio of 10% could save approximately 50% of the cooling air. It is observed that the liquid droplets mostly follow the main sweeping flow and its vortical structure and horseshoe vortices, but with a phase lag between the droplets and the main sweeping jet. This phase lag further enhances both temporal and spatial film cooling surface protection during the sweeping motion.

References

1.
Hossain
,
M. A.
,
Prenter
,
R.
,
Lundgreen
,
R. K.
,
Ameri
,
A.
,
Gregory
,
J. W.
, and
Bons
,
J. P.
,
2018
, “
Experimental and Numerical Investigation of Sweeping Jet Film Cooling
,”
ASME J. Turbomach.
,
140
(
3
), p.
031009
.
2.
Hossain
,
M. A.
,
Agricola
,
L.
,
Ameri
,
A.
,
Gregory
,
J. W.
, and
Bons
,
J. P.
,
2019
, “
Sweeping Jet Film Cooling on a Turbine Vane
,”
ASME J. Turbomach.
,
141
(
3
), p.
031007
.
3.
Hossain
,
M. A.
,
Asar
,
M. E.
,
Gregory
,
J. W.
, and
Bons
,
J. P.
,
2020
, “
Experimental Investigation of Sweeping Jet Film Cooling in a Transonic Turbine Cascade
,”
ASME J. Turbomach.
,
142
(
4
), p.
041009
.
4.
Hossain
,
M. A.
,
Ameri
,
A.
,
Gregory
,
J. W.
, and
Bons
,
J. P.
,
2020
, “
Sweeping Jet Film Cooling at High Blowing Ratio on a Turbine Vane
,”
ASME J. Turbomach.
,
142
(
12
), p.
121010
.
5.
Hossain
,
M. A.
,
Ameri
,
A.
,
Gregory
,
J. W.
, and
Bons
,
J. P.
,
2021
, “
Experimental Investigation of Innovative Cooling Schemes on an Additively Manufactured Engine Scale Turbine Nozzle Guide Vane
,”
ASME J. Turbomach.
,
143
(
5
), p.
051004
.
6.
Spens
,
A.
, and
Bons
,
J. P.
,
2021
, “
Experimental Investigation of Synchronized Sweeping Jets for Film Cooling Application
,”
AIAA Scitech 2021 Forum
,
Virtual Event
,
Jan. 11–15 and 19–21
,
AIAA 2021-2003
.
7.
Abdelmaksoud
,
R.
, and
Wang
,
T.
,
2022
, “
Recent Advances in Heat Transfer Applications Using Sweeping Jet Fluidic Oscillators
,”
Int. J. Energy Clean Environ.
,
24
(
2
), pp.
21
87
.
8.
Zhou
,
W.
,
Wang
,
K.
,
Yuan
,
T.
,
Wen
,
X.
,
Peng
,
D.
, and
Liu
,
Y.
,
2022
, “
Spatiotemporal Distributions of Sweeping jet Film Cooling with a Compact Geometry
,”
Phys. Fluids
,
34
(
2
), p.
025113
.
9.
Takagi
,
T.
, and
Ogasawara
,
M.
,
1974
, “
Some Characteristics of Heat and Mass Transfer in Binary Mist Flow
,”
Proceedings of 5th Intl. Heat Transfer Conference
,
Tokyo, Japan
,
Sept. 3–7
, pp.
350
354
.
10.
Mori
,
Y.
,
Hijikata
,
K.
, and
Yasunaga
,
T.
,
1982
, “
Mist Cooling of Very Hot Tubules With Reference to Through-Hole Cooling of Gas Turbine Blades
,”
Intl. J. Heat Mass Transfer
,
25
(
9
), pp.
1271
1278
.
11.
Nirmalan
,
N. V.
,
Weaver
,
J. A.
, and
Hylton
,
L. D.
,
1998
, “
An Experimental Study of Turbine Vane Heat Transfer With Water–Air Cooling
,”
ASME J. Turbomach.
,
120
(
1
), pp.
50
60
.
12.
Zhao
,
L.
, and
Wang
,
T.
,
2014
, “
An Experimental Study of Mist/Air Film Cooling on a Flat Plate With Application to Gas Turbine Airfoils—Part I: Heat Transfer
,”
ASME J. Turbomach.
,
136
(
7
), pp.
071006
.
13.
Zhao
,
L.
, and
Wang
,
T.
,
2014
, “
An Experimental Study of Mist/Air Film Cooling on a Flat Plate With Application to Gas Turbine Airfoils: Part 2—Two-Phase Flow Measurements and Droplet Dynamics
,”
ASME J. Turbomach.
,
136
(
7
), p.
071007
.
14.
Ragab
,
R.
, and
Wang
,
T.
,
2018
, “
An Experimental Study of Mist Film Cooling With Fan-Shaped Holes on an Extended Flat Plate—Part 1: Heat Transfer
,”
ASME J. Heat Transfer
,
140
(
4
), p.
042201
.
15.
Ragab
,
R.
, and
Wang
,
T.
,
2018
, “
An Experimental Study of Mist Film Cooling With Fan-Shaped Holes on an Extended Flat Plate—Part 2: Two-Phase Flow Measurements and Droplet Dynamics
,”
ASME J. Heat Transfer
,
140
(
4
), p.
042202
.
16.
Ragab
,
R.
, and
Wang
,
T.
,
2012
, “
An Investigation of Applicability of Transporting Water Mist for Cooling Turbine Vanes
,”
ASME Turbo Expo
, Paper No. HT2013-17150, pp.
1809
1821
.
17.
Ragab
,
R.
, and
Wang
,
T.
,
2013
, “
Investigation of Applicability of Using Water Mist for Cooling High-Pressure Turbine Components via Rotor Cavity Feed Channels
,”
Proceedings of ASME Summer Heat Transfer Conference
, Paper No.: HT2013-17150.
18.
Wang
,
T.
, and
Ragab
,
R.
,
2019
, “
Investigation of Applicability of Transporting Water Mist for Cooling Turbine Blades
,”
ASME J. Therm. Sci. Eng. Appl.
,
12
(
1
), p.
011009
.
19.
Menter
,
F. R.
,
1994
, “
Two-Equation Eddy-Viscosity Turbulence Models for Engineering Applications
,”
AIAA J.
,
32
(
8
), pp.
1598
1605
.
20.
Abdelmaksoud
,
R.
, and
Wang
,
T.
,
2021
, “
A Numerical Investigation of Mist Cooling Through a Conjugate, Rotating 3D Gas Turbine Blade With Internal, External, and Tip Cooling
,”
ASME J. Therm. Sci. Eng. Appl.
,
13
(
2
), p.
021004
.
21.
Abdelmaksoud
,
R.
, and
Wang
,
T.
,
2020
, “
Simulation of Mist Cooling in a Conjugate, 3-D gas Turbine Vane With Internal Passage and External Film Cooling
,”
Intl. J. Heat Mass Transfer
,
160
, p.
120197
.
22.
Wang
,
T.
,
Zhao
,
L.
, and
Abdelmaksoud
,
R.
,
2022
, “
A Validation of a Two-Phase CFD Model Air/Mist Film Cooling with Experimental Details ─ Part I: Development of an Experimental Test Facility
,”
ASME J. Therm. Sci. Eng. Appl.
,
14
(
11
), p.
111009
.
23.
Abdelmaksoud
,
R.
,
Wang
,
T.
, and
Zhao
,
L.
,
2022
, “
Validation of a Two-Phase CFD Model Air/Mist Film Cooling With Experimental Details ─Part II: CFD Model Validation
,”
ASME J. Therm. Sci. Eng. Appl.
,
14
(
11
), p.
111010
.
24.
O’Rourke
,
P. J.
, and
Amsden
,
A. A.
,
1987
, “
The Tab Method for Numerical Calculation of Spray Droplet Breakup
,” SAE Technical Paper No. 872089.
25.
O'Rourke
,
P. J.
,
1981
, “
Collective Drop Effects on Vaporizing Liquid Sprays
,” Doctoral Dissertation,
Princeton University
,
Princeton, NJ
.
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