This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Photographic Observation of Knock with a Rapid Compression and Expansion Machine
Annotation ability available
Sector:
Language:
English
Abstract
A new type of rapid compression and expansion machine (RCEM) has been developed, and typical knock scenes were clearly recorded with a high speed laser shadowgraph at a speed of 100,000 frames per second.
The RCEM is intended to simulate combustion in an automotive engine. Its piston is driven by an electrohydraulic servo system and is allowed to execute continuous reciprocations up to five times. The combustion chamber is a simple pancake type with an ignition plug on its side and the whole inner view is observable through a glass window on the top.
Knock observation was made under the following conditions; (1) the fuel was butane, (2) the charged gas was homogeneously pre-mixed and static, (3) the piston executed a single reciprocation. Other parameters were set for heavy knock to occur.
The shadowgraph observation revealed that autoignition occurs at a point in the endgas far from a normal flame front and is reflected by the opposite wall. Comparison with dynamic pressure measurements suggests that the wave is a shock wave, which causes an abrupt pressure rise followed by vibration. Knock can be explained by the autoignition and the subsequent pressure wave propagation process.
Recommended Content
Technical Paper | Knock (Detonation) Control by Engine Combustion Chamber Shape |
Technical Paper | The Effect of Combustion Chamber Geometry on HCCI Operation |
Technical Paper | A Study of a DISI Engine with a Centrally Located High-pressure Fuel Injector |
Authors
- Tadakuni Hayashi - TOYOTA Central Research and Development Laboratories, Inc.
- Masahiro Taki - TOYOTA Central Research and Development Laboratories, Inc.
- Shinji Kojima - TOYOTA Central Research and Development Laboratories, Inc.
- Teruaki Kondo - TOYOTA Central Research and Development Laboratories, Inc.
Citation
Hayashi, T., Taki, M., Kojima, S., and Kondo, T., "Photographic Observation of Knock with a Rapid Compression and Expansion Machine," SAE Technical Paper 841336, 1984, https://doi.org/10.4271/841336.Also In
References
- Withrow L. Rassweiler G. M. “Slow Motion Shows Knocking and Non-knocking Explosions” SAE Transactions 39 2 297 303 1936
- Male T. “Photographic at 500,000 Frames per Second of Combustion and Detonation in a Reciprocating Engine” The Third Symposium on Combustion, Flame and Explosion Phenomena 721 726 Williams & Wilkins Baltimore 1949
- Miller CD. “Knock as Shown by Photographs Taken at 40,000 and 200,000 Frames per Sec” SAE Quarterly Transactions 1 1 99 143 January 1947