0
Research Papers: Internal Combustion Engines

An Experimental Study of Spark Anemometry for In-Cylinder Velocity Measurements

[+] Author and Article Information
D. P. Gardiner, G. Wang, M. F. Bardon, M. LaViolette

Department of Mechanical Engineering, Royal Military College of Canada, Kingston, ON K7K 7B4, Canada

W. D. Allan

Department of Mechanical Engineering, Royal Military College of Canada, Kingston, ON K7K 7B4, Canadabilly.allan@rmc.ca

J. Eng. Gas Turbines Power 130(4), 042801 (Apr 23, 2008) (10 pages) doi:10.1115/1.2898835 History: Received December 01, 2006; Revised January 23, 2008; Published April 23, 2008

It has been demonstrated by previous researchers that an approximate value of the bulk flow velocity through the spark plug gap of a running spark ignition engine may be deduced from the voltage and current wave forms of the spark. The technique has become known as spark anemometry and offers a robust means of velocity sensing for engine combustion chambers and other high temperature environments. This paper describes an experimental study aimed at improving performance of spark anemometry as an engine research tool. Bench tests were conducted using flow provided by a calibrated nozzle apparatus discharging to atmospheric pressure. While earlier studies had relied upon assumptions about the shape of the stretching spark channel to relate the spark voltage to the flow velocity, the actual spark channel shape was documented using high-speed video in the present study. A programmable ignition system was used to generate well-controlled constant current discharges. The spark anemometry apparatus was then tested in a light duty automotive engine. Results from the image analysis of the spark channel shape undertaken in the present study have shown that the spark kernel moves at a velocity of less than that of the freestream gas velocity. A lower velocity threshold exists below, which there is no response from the spark. It is possible to obtain a consistent, nearly linear relationship between the first derivative of the sustaining voltage of a constant current spark and the freestream velocity if the velocity falls within certain limits. The engine tests revealed a great deal of cycle-to-cycle variation in the in-cylinder velocity measurements. Instances where the spark restrikes occur during the cycle must also be recognized in order to avoid false velocity indications.

FIGURES IN THIS ARTICLE
<>
Copyright © 2008 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Simplified relationship between velocity and spark length

Grahic Jump Location
Figure 2

Components of measured spark voltage

Grahic Jump Location
Figure 3

Comparison of conventional decaying current spark and constant current spark

Grahic Jump Location
Figure 4

Examples of 10mA constant current sparks at different velocities (8000frames∕s and 125μs framing interval)

Grahic Jump Location
Figure 5

Effect of velocity on voltage wave forms of 10mA constant current sparks

Grahic Jump Location
Figure 6

Relationship between velocity of spark head and freestream velocity

Grahic Jump Location
Figure 7

Relationship between first derivative of spark length and freestream velocity

Grahic Jump Location
Figure 8

Relationship between first derivative of spark length and velocity of spark head

Grahic Jump Location
Figure 9

(a) Relationship between first derivative of spark voltage and freestream velocity. (b) Relationship between first derivative of spark voltage and freestream velocity using 63.5mm flow nozzle.

Grahic Jump Location
Figure 10

First derivative of spark voltage (dV∕dt) at low velocities (10mA constant current spark)

Grahic Jump Location
Figure 11

Wave forms from in-cylinder velocity measurements

Grahic Jump Location
Figure 12

Cycles without restrike events

Grahic Jump Location
Figure 13

Cycles with pronounced restrike events

Grahic Jump Location
Figure 14

Cycles with voltage plateaus due to minor restrike events

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In