Abstract

In high-speed gear systems for aeroengines, reducing the fluid dynamic loss, which accounts for the majority of power loss, can significantly improve fuel economy. However, few practical numerical examples are available regarding high-speed gas–liquid two-phase flows involving gear meshing and gear shrouds (gear enclosures, which are effective for loss reduction). Therefore, in this study, the porosity method for object boundaries including the gear meshing, the volume of fluid method, and the surface compression method for the gas–liquid interface was used as fast and numerically stable calculation methods. In addition, a gap was provided at the contact surface of the gear tooth surface to improve the calculation stability, and the oil properties were set considering the difference between the flow resistance in a two-phase flow and that in a single-phase flow (due to the separation of oil particles) to improve the calculation accuracy. To validate the numerical simulation method, a two-axis helical gearbox with a maximum peripheral speed of 100 m/s with specifications equivalent to aeroengine gears was used, and the air flow, oil flow, and fluid dynamic losses were validated. Once the practical accuracy was confirmed, the numerical simulation was used to understand the relationship between air and oil flows, torque, and the effect of the shroud. Consequently, the fluid dynamic loss could be classified phenomenologically.

References

1.
Peltry-Johnson
,
T. T.
,
Kahraman
,
A.
,
Anderson
,
N. E.
, and
Chase
,
D. R.
,
2008
, “
An Experimental Investigation of Spur Gear Efficiency
,”
ASME J. Mech. Des.
,
130
(
6
), p.
062601
.10.1115/1.2898876
2.
Concli
,
F.
, and
Gorla
,
C.
,
2016
, “
Numerical Modeling of the Power Losses in Geared Transmissions: Windage, Churning and Cavitation Simulations With a New Integrated Approach That Drastically Reduces the Computational Effort
,”
Tribol. Intl.
103
(
C
), pp.
58
68
.10.1016/j.triboint.2016.06.046
3.
Liu
,
H.
,
Arfaoui
,
G.
,
Stanic
,
M.
,
Montigny
,
L.
,
Jurkschat
,
T.
,
Lohner
,
T.
, and
Stahl
,
K.
,
2019
, “
Numerical Modelling of Oil Distribution and Churning Gear Power Losses of Gearboxes by Smoothed Particle Hydrodynamics
,”
Proc. Inst. Mech. Eng.
,
233
(
1
), pp.
74
86
.10.1177/1350650118760626
4.
Arisawa
,
H.
,
Nishimura
,
M.
,
Imai
,
H.
, and
Goi
,
T.
,
2014
, “
Computational Fluid Dynamics Simulations and Experiments for Reduction of Oil Churning Loss and Windage Loss in Aeroengine Transmission Gears
,”
ASME J. Eng. Gas Turbines Power
,
136
(
9
), p.
092604
.10.1115/1.4026952
5.
Matsumoto
,
S.
,
Asanabe
,
S.
,
Takano
,
K.
, and
Yamamoto
,
M.
,
1985
, “
Evaluation Method of Power Loss in High-Speed Gears
,”
Proceedings of Japan Society of Lubrication Engineers International Tribology Conference
, Tokyo, Japan, July 8–10, pp.
1165
1170
.10.1016/j.biosystemseng.2008.03.002
6.
Chanenet
,
C.
,
Ville
,
F.
, and
Velex
,
P.
,
2016
, “
Thermal Behavior of a High-Speed Gear Unit
,”
GEAR Technology, AGMA
,
Elk Grove Village, IL
, pp.
38
41
.https://www.geartechnology.com/ext/resources/issues/0116x/thermal.pdf
7.
Hirt
,
C. W.
, and
Nichols
,
B. D.
,
1981
, “
Volume of Fluid (VOF) Method for the Dynamics of Free Boundaries
,”
J. Comput. Phys.
,
39
(
1
), pp.
201
225
.10.1016/0021-9991(81)90145-5
8.
Hirt
,
C. W.
, and
Sicilian
,
J. M.
,
1985
, “
A Porosity Technique for the Definition of Obstacles in Rectangular Cell Meshes
,”
Proceedings of Fourth International Conference Numerical Ship Hydrodynamics
, Washington, DC, Sept. 24–27.https://trid.trb.org/view/394627
9.
Rusche
,
H.
,
2002
, “
Computational Fluid Dynamics of Dispersed Two-Phase Flows at High Phase Fraction
,”
Ph.D. thesis
,
Imperial College London
,
London, UK
.https://spiral.imperial.ac.uk/handle/10044/1/8110
10.
Flow Science, Inc.
,
2016
, “
FLOW-3D/MP®
Users Manual Version 6.0,”
Flow Science
,
Santa Fe, NM
.https://www.flow3d.com
11.
Saegusa
,
D.
, and
Kawai
,
S.
,
2014
, “
CFD Analysis of Lubricant Fluid Flow in Automotive Transmission
,”
SAE
Paper No. 2014-01-1772. 10.4271/2014-01-1772
12.
Delgado
,
I. R.
, and
Hurrell
,
M. J.
,
2017
, “
Baseline Experimental Results on the Effect of Oil Temperature on Shrouded Meshed Spur Gear Windage Power Loss
,”
ASME
Paper No. DETC2017-67818. 10.1115/DETC2017-67818
13.
Houjoh
,
H.
, and
Iino
,
T.
,
2015
, “
Experimental Investigation of the Possibility of a Self-Vacuuming Gearbox for Reducing Windage Loss
,”
ASME
Paper No. DETC2015-47257. 10.1115/DETC2015-47257
14.
Arisawa
,
H.
,
Shinoda
,
Y.
,
Noguchi
,
Y.
,
Goi
,
T.
,
Banno
,
T.
, and
Akahori
,
H.
,
2019
, “
Development of a Flow Visualization Borescope and a Two-Phase Flow Probe for Aeroengine Transmission Gears
,”
ASME J. Eng. Gas Turbines Power
,
141
(
9
), p.
091013
.10.1115/1.4043993
15.
Diab
,
Y.
,
Ville
,
F.
,
Houjoh
,
H.
,
Sainsot
,
P.
, and
Velex
,
P.
,
2005
, “
Experimental and Numerical Investigations on the Air-Pumping Phenomenon in High-Speed Spur and Helical Gears
,”
Proc. Inst. Mech. Eng.
,
219
(
8
), pp.
785
800
.10.1243/095440605X31652
16.
Arisawa
,
H.
,
Tanaka
,
M.
,
Hashimoto
,
H.
,
Goi
,
T.
,
Banno
,
T.
, and
Akahori
,
H.
,
2023
, “
Fluid Dynamic Loss Model With Wide Applicability for Aeroengine Transmission Gears
,”
ASME
Paper No. GT2023-100547. 10.1115/GT2023-100547
17.
Dawson
,
P. H.
,
1984
, “
Windage Loss in Larger High-Speed Gears
,”
Proc. Inst. Mech. Eng.
,
198
(
1
), pp.
51
59
.10.1243/PIME_PROC_1984_198_007_02
18.
Arisawa
,
H.
,
2023
, “
Fluid Dynamic Loss in Aeroengine Transmission Gears
,” Ph.D. thesis,
University of Tokyo
,
Tokyo, Japan
.
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