This document presents an approach to reducing frictional losses in heavy duty diesel engines through surface texturing to reduce hydrodynamic friction. The study textures cylinder liner samples with different depth elliptical textures and tests them on a tribometer. Results show the textured surfaces have less wear and increased oil film thickness compared to untreated surfaces, leading to lower friction in the hydrodynamic lubrication regime. The conclusions are that the novel surface texturing decreases hydrodynamic friction and only the texture depth differs between the tested samples.

1. An Approach to Reduction of Frictional Losses
in Heavy Duty Diesel Engine by Reducing
Hydrodynamic Frictional losses.
SEMINAR PRESENTATION
Name: Nagesh Dewangan
Course: M.Tech.
(MET)
Ad No. :17MT001503
IIT (ISM), Dhanbad
Session 2017-18

2. Table of Contents
1. Introduction
2. Experimental
Method
3. Results
4. Discussions
5. Conclusions

3. Introduction
 Power Cylinder Unit (PCU) is the single largest
Contributor to frictional losses about 50%.
 Much attention is paid for reducing boundary and mixed
lubrication regimes.
 Large portion of frictional losses in PCU occur in
Hydrodynamic lubrication Regime.
Disadvantages-
1. Viscosity of lubricant is dominating parameter.
2. Main part significant for controlling friction is Plateau Part.
Continued…

4. Introduction
 The aim of this study is to reduce
Hydrodynamic losses in PCU through Surface
Texturing.
1. Qiu and Konsari analysed frictional behavior of elliptical
and circular dimples.
2. Podgornik et al examined different textured in full film
lubrication in Tribometer.

5. Experimental Method
2.1 Manufacturing of Textured Samples
 CNC milling machine was used to machine textures on
cylinder liner sample. Sample is of size 50*10 mm2 .
 Two different depth were machined 20µm and 100µm.
 Orientation of texture is at 20 degree with the reference
direction of motion.
2.2 Tribometer
 A tribometer is used the frictional properties of reference
surfaces.
 Input signal were temperature, rec. frequency, load.
 Measured output were friction force and resistivity coeff.

6. Diagrams
 Tribometer Texture Surface

7. Results
3.1 Evaluation of Wear and Texture Geometry
1. Abrasive wear on
reference surface.
2. No abrasive wear on
textured surface.
3. But textures contain
wear particles.
Continued…

8. Results
3.2 Evaluation of the Stability of Input Signals
To gain better representation of the input signals, these are
recalculated
 Sliding speed is calculated from reciprocating frequency
 Oil dynamic viscosity is calculated from temperature
 Contact pressure is calculated from load
3.3 Evaluation of lubrication Regimes and Experimental
Outputs

9. Variation of Contact Pressure

10. Variation of Dynamic Viscosity

11. Discussions
4.1. Behavior of Oil Film Thickness and Textures.
 A significant increase in the oil film thickness of passage of
a texture.
 Amount of contact increases for the textured surface
compared to the reference surface. Thus, µ is higher for
texture.
 Resistive signal increases for the textured surfaces which
indicates that the amount of metal-to-metal contact increased
for the textured surface compared to the reference surface.

12. Discussions
4.2. Texture Properties Applicable to a Tribosystem in
Hydrodynamic Lubrication.
 It is not optimal to put textures in the reversal zones of
a tribosystem due to the following:
1.At reversal zones.
2.If temperatures are high.
3.If contact pressure in the tribosystem is high.
Continued…

13. Discussions
 Area density of texturing is controlled, oil thickness between
the plateau of the cylinder liner and the piston ring remain
constant for crank angle 21–159 between 20-50%. Thus be
significantly higher oil film thickness, so it is possible to
decrease the hydrodynamic friction.
 The average oil film thickness with inclusion of the textures is
greatly increased, and thus friction will decrease greatly.
Continued…

14. Conclusions
The following conclusions can be drawn from this
study:
 Only parameter that differs between the two
types is the texture depth.
 Textured surface exhibits smaller signs of
abrasive wear.
 The novel type of surface texturing presented in
the study decreases friction in the hydrodynamic
regime.

15. Reference
Staffan Johansson et al, “An Approach to Reduction of
Frictional Losses in a Heavy-Duty Diesel Engine by
Reducing the Hydrodynamic Frictional Losses”,
Advances in Tribology, Volume 2017 (2017), Article ID
9240703,

16. Thank You