Dynamics of an IC Engine Valvetrain By Mr. Narayan Sanjay Susange MIS : 121495019 Under the Guidance of Dr. D. N. Malkhede (COEP) Dr. C. M. Sewatkar (COEP) Mr. Naresh Gandhi (KOEL) Mr. Aniket Basu (KOEL) DISSERTATION REPORT ON
Dynamics of an IC Engine Valvetrain
ByMr. Narayan Sanjay Susange
MIS : 121495019Under the Guidance of
Dr. D. N. Malkhede (COEP)Dr. C. M. Sewatkar (COEP)Mr. Naresh Gandhi (KOEL)
Mr. Aniket Basu (KOEL)
DISSERTATION REPORT
ON
Outline Project definition. Introduction to Valvetrain. Literature Review Steps in Project. Simulation Work. Validation. Design Modification. Conclusion
Project Definition
To study the dynamic behavior of valvetrain system at
elevated 3300 rpm from it’s max rated 3000 rpm.
Further attempt to reduce the dynamic impact of these
elements on performance of valvetrain.
Introduction to Valvetrain. Valve Valve Seat Valve Spring Rocker Arm Push Rod Tappet Camshaft
Literature Review Dynamic Phenomenon prediction
Steps in Project Literature Review Modelling Parts in Creo. FEA Analysis in HyperMesh. VALKIN and VALDYN model in RICARDO. Validate model with experimental results. Design modification Interpret results.
Need of Project Typical engine used in fire fighting. Requirement of high capacity engine is generated from
marketing dept. Time restriction for building new engine. Started modifying existing engine to match requirement. After modification found that valvetrain is weakest
element. Started generating data with experimentation.
Simulation RICARDO VALKIN and VALDYN. Dimensional inputs are taken from model. Mass and stiffness values are taken from FEA model. Run the simulation at various rpm such 840, 1800, 2600,
3000 and 3300. Experimental results of pushrod forces at 3000 rpm are
taken validation. Model Validated.
VALKIN Model
Lift. Velocity. Acceleration. Wear rate. Contact
Forces. Contact
stresses. Oil film
thickness.
Lift. Velocity. Acceleration. Dynamic
Forces.
VALDYN Model
Inputs for VALDYN ModelSr. No. Ricardo Model Components Damping
Stiffness MassDamping Coefficient
(N/mm) (gm)
1 X support 1750 82642 926.435711 0.1
2 Y support 1750 70744 1082.24726 0.1
3 1/2 rocker + valve 337.9829071 24213.075 209.68 0.075
4 Valve seat 348.4250278 100000 30.35 0.1
5 1/2 pushrod + 1/2 rocker 140.063821 17032.361 115.18 0.05
6 Half pushrod 173.6294385 27531.673 109.5 0.05
7 Camshaft tappet 2402.642295 34000 38.5 1.05
8 Camshaft bending 387.2983346 100000 150 0.05
9 Rocker + pushrod 1/3 387.2983346 100000 150 0.05
10 2/3 pushrod 229.6153616 19841.27 118.1 0.075
Pushrod Forces @ 3300 rpm
Validation of Simulation Model
0 1000 2000 3000 4000 5000 6000 7000 8000
-100
0
100
200
300
400
500
600
700
800
PUSHROD FORCE
Time in milliseconds
Forc
e in
N
Simulation Model Result Experimental Result
@ 3000 RPM
Valve Lift
Valve Seat Force
Rocker Valve Contact Forces
Tappet Force
Cam Forces
Spring Surge
-20 -5 10 25 40 55 70 85 100 115 130 145 1600
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
Cam ProfileNew profile
old profile
Rotation Angle in Deg
Cam
Lift
in m
m
Design Modification
Spring Surge
Valve Lift
Valve Seat Forces
Rocker Valve Contact Forces
Push Rod Forces
Tappet Force
Cam Force
0 1000 2000 3000 4000 5000 6000 7000 8000-50150350550750950
11501350155017501950215023502550275029503150
Old Cam
Updated cam
Time in milliseconds
Forc
e in
N
Pushrod Forces Comparison
Sheet Data of Comparison
Model- 2600 half model
3000 half model
3300 half model
2600 half model with updated cam profile
3300 half model with updated cam profile
Contact loss Rocker-Valve 1 2 4 0 1
Jump in mm 0 -0.4 1 0 0.2
Bounce in mm 0.015 0.25 0.4 0 0
Spring Surge in mm 1 2.75 3.6 0.1 1
Push Rod Forces in N 2650 2800 (5.6%) 3080 (16.22%) 1350 (-49.50) 1850 (39.90%)
Valve Forces in N 950 1700 (78.50%) 1350 (42.10%) 680 (-28.42) 1200 (-11.11%)
Tappet Forces in N 2840 3180 (12%) 3250 (14.43%) 1450 (-48.94%) 2050 (-36.92%)
Cam Forces in N 3000 3450 (15%) 3420 (14%) 1500 (-50%) 2200 (-35.67%)
Valve Seat Force in N 2750 2250 (-18.18%) 2300 (-16.36%) 2250 (-18.18%) 1850 (-19.56%)
Valve Seat Bounce pts 2 4 4 2 1
Conclusion
At 3000 & 3300 rpm, Valvetrain shows significant dynamic Effects in terms of Spring surge, Valve jump and bounce, Pushrod forces and contact loss.
This will definitely affect the valvetrain performance and it’s life.
Modified cam profile suppresses almost all the unaccepted dynamic effects which is also a better for normal rpm run.
Further modification in valvetrain parts like pushrod, tappet will not enhance dynamic effects.
Thank you