صفحه 1:
Produced By:Ali Reza Hosseinian
Master : Eng. Yousefi Rad
Department of Mechanical Engineering,
University of Khayyam
May 22, 2012
صفحه 2:
In order to develop more efficient engines,
it is essential to optimize the lubrication
circuit of the power train systems.
Two elements have been added to the
lubrication circuit in the modified engine.
These elements are hydraulic lifters and an
Anti-drain valve.
‘ The analyses are done by Flowmaster7.6
and AVL EXCITE7.02 software and an
accessory code.
’ Finally, theoreti I results are validated by
صفحه 3:
Lubrication Circuit
Bearing Map
Chain Tensioner
Flowmaster
¥ Journal Bearings
صفحه 4:
Modern engines are being designed to operate
at high engine speeds and loads. In order to
fulfill the requirements of developing new
engines, lubrication system must be improved.
Yiging Yuan et al, in 2007, established a
methodology for predicting lubrication flow
in the rod bearings and oil circuits that can
be used to guide engineering designs.
صفحه 5:
Yaguo Lu et al. [10], in 2009, developed a
software for simulating aero-engine
lubrication system.
In this paper, two important components,
chain tensioner and anti-drain valve, have
been investigated as well as other
components in the lubrication system.
صفحه 6:
Petrol CNG-Petrol
1596 1698
10.8 درو
Mechanical Hydraulic
No. Yes
No Yes
NBR Poly Amid
835 eee)
عمأومع رت
Fuel type
Displaceme
nt (cc)
‘Compressio
واه و
Lifter type
Anti drain
valve
Piston
cooling jet
Chain
tensioner
Engine
description
There are three
important reasons for
improving the base
engine to the
modified engine:
(1) using inexpensive
and locally abundant
CNG fuel,
(2) demanding higher
power and
(3) modifying
weaknesses of the
base engine. The
صفحه 7:
This test is applicable to Diesel and Gasoline
engines.
After installing the sensors in particular locations
of lubrication circuit like the main gallery, oil
pump outlet, oil filter inlet and outlet, the end
side of the hydraulic lifter gallery, the engine is
configured on the dynamometer and prepared
for lubrication functional test. This test is divided
into steady state and transient parts.
صفحه 8:
In the steady state
part the oil
temperature is fixed
at 90 and 130 °C and
for each temperature
engine speed is swept
from idle to rated
speed and data
acquisition is
performed for each
point.
In the transient part,
on the other hand, the
time of delivering oil
to different elements
AS Sears ie Paetie © Ba
صفحه 9:
The flowmaste
v7.6 program
The Flowmaster is a
one-dimensional fluid
flow program based
on the theory of
stream lines. The
physical basis for this
program comprises
empirical and
analytical equations
for mass, momentum,
and energy plus an
extensive database to
describe the system
parts.
صفحه 10:
Bearing calculations are carried out in AVL-
EXCITE software by solving the Reynolds
equation.
The Flowmaster can find the needed oil flow
rate of bearings by a simple formula and
iterative method. Moreover, this allows the
user to supply an oil flow rate map for
bearings by supplementary software like AVL-
EXCITE.
صفحه 11:
Bearing
calculation
One of the most
important design
parameters in bearing
design which should
always be verified is
minimum oil film
thickness. Our
calculations in AVL-
EXCITE software
demonstrate that the
value of this parameter
for all bearings are in
the safe margin and
the requirements in Engine Spoed im]
accordance with design
soo 1009 2000 3000 4000 5000 5500
صفحه 12:
“Chain tensioner comprises a plunger and
cylinder which utilize oil to damp the rate of
plunger reciprocating motion.
The base engine has a chain tensioner made
from NBR (Nitride Butyl Rubber) wearing
unacceptably in hard conditions like
durability cycles which is shown in Figure.
Intensive wearing of the original chain
tensioner had been frequently reported from
after sale market. This defect was also found
on the e1 engine standard durability cycles in
صفحه 13:
Consequently, the problem was considered
in two points of view:
improper material
inappropriate lubrication
صفحه 14:
Anti-drain valve
Hydraulic lifter and piston
cooling jet
The base engine is OHV A new element added in
(Overhead Valve) type the modified engine is
and mechanical lifter is an antidrain valve with
used in its valve train a low hydraulic loss.
system. This is used to avoid oil
For in order to improve draining from hydraulic
performance in the lifter gallery due to the
modified engine, gravity when engine is
hydraulic lifter is stopped.
utilized.
صفحه 15:
1- Validation of Simulation Results
A precise way to
evaluate the ability of
the Flowmaster in
predicting engine
lubrication circuit is
comparing calculated
oil pressure at some a ee
important nodes and الو ا لو cee
flow rate of main
صفحه 16:
2- Results of chain tensioner با
Chain tensioner is a
compound element in
lubrication circuit. As
considered in section 6
lubrication is one of the
most important problems
which had to be figured
out properly. To solve this ea
2
1
1
problem, oil flow rate in م۳ ok sua
chain tensioner should be con (imal)
increased and oil
صفحه 17:
3- Results of Hydraulic Lifter
As mentioned before, during
the oil was delivered to the 5
hydraulic lifter at the engine 2
startup should be as low as
possible.
As can be noticed in Figures 13
and 14, the effect of different
oil temperature on the oil
delivery time at engine startup 2
conditions is shown in these
figures. When oil temperature ‘lt Temperser Pf
rises, the oil viscosity is a aa’ 8
decreased and the adhesive ات عو ع ع م oie
force between oil molecules
and gallery walls is decreased
Time [See]
0 2
om wT hm م 10 10 18 Ww
صفحه 18:
4- Results of Piston Cooling
Jet (PCJ)
Oil flow rate of each
engine component is
shown in Figure 15. As it
can be considered, PCJs
oil flow rate is definitely
negligible in comparison
with the total engine flow
rate. Therefore, it does
not have any defect on
oil feeding of other
components in the
lubrication system
صفحه 19:
5- Results of Oil Pump
Corresponding to the changes made in the base
engine, it should be verified if original oil pump
covers the lubrication circuit requirements or not.
These changes included:
adding hydraulic lifters and PCJs as lubrication
system components
‘increasing chain tensioner oil flow rate
‘increasing main and pin bearing clearances
صفحه 20:
The aim of this article is introducing a
simple and robust methodology to
simulate engine lubrication systems
duringengine design and development
process.
Also, the effect of adding new elements
like chain tensioner and antidrain valve
on oil pump behavior and obligatory
minimum pressure in network's vital
ی فا ار عن ی ارت
صفحه 21:
1 1 , it will be valuable if
the dynamic behavior of oil pump and
bearings be simulated at engine start
up condition. To simulate this
phenomenon, the reaction between air
and oil as a two phase flow should be
considered.
صفحه 22:
[1] Lo R. S., "Digital Simulation of Engine Lubrication Systems", SAE
Paper 710205, 1971.
[2] Neu E. A., Wade J. A. and Chu A. C., "Simulating the Lubrication
System of a diesel engine", SAE Paper 770032, 1977.
[3] Hass A., Esch T., Fahl E., Kreuter P,, Pischinger F., "Optimized design
of the lubrication system of modern combustion engines", SAE
912407,
1991.
[4] Mian M., "Design and analysis of engine lubrication system", SAE
970637, p.219-32, 1997
[5] Chun, S. M., Park, ¥. H., Jang, S., "A study on engine lubrication
system by optimized network analysis- part |: case study", SAE 2000-
01-2921, 2000.
صفحه 23:
[6] Chun S. M., Park ¥. H., Jang S., “A study on engine lubrication
system by optimized network analysis- part Il: parametric study", SAE
2000-01-2923, 2000.
[7] Felix, K. and Uwe, K., "Simulating Engine Lubrication Systems with
1-D Fluid Flow Models", SAE World Congress in Detroit, Michigan,
March 6-9, 2000.
[8] Chun, S.M., "Network analysis of an engine lubrication system",
Tribology
International 36-2003, p.609-617
[9] Yiging Yuan, Wei Tao, Eysion A. Liu, Gary C. Barber et.al, “Engine
lubrication system analysis by considering aeration and cavitation with
the rotating oil supply passage", Tribology Transactions; Jan-Mar 2007;
50, 1; ProQuest Science Journals pg. 39.
[10] Yaguo L., Zhenxia L. and Shengqin H., "Numerical Simulation of
Aero-Engine Lubrication System", Journal of Engineering for Gas
Turbines
and Power. MAY 2009. Vol. 131 / 034503-1.
