Study on Similarity of Pumping Flow in Engine Crankcase

2009-32-0051

11/03/2009

Event
Small Engine Technology Conference & Exposition
Authors Abstract
Content
For the prediction of pumping loss in the engine crankcase at the early stage of engine design, a similarity law of the pumping loss on parallel cylinders with the phase difference of 180 degrees has been derived from the sum of the power loss due to the drag force of airflow through the cylinder bulkhead holes and the inertia force of fluid. It has been found that the mean effective pressure in the crankcase is in proportion to the square of the mean flow velocity at the bulkhead holes. Then, in order to validate the similarity law, by using a prototype engine with inline four cylinders, the pumping loss was estimated by subtracting the frictional loss with special pistons that had air holes, from the power loss in which the area of the bulkhead holes and engine speed were changed. The experimental results of the pumping loss were normalized by the similarity law. As a consequence, it has been shown that the pumping loss obeys the law. Thus, the similarity law is valid for pumping loss in the crankcase.
Meta TagsDetails
DOI
https://doi.org/10.4271/2009-32-0051
Pages
8
Citation
Arisawa, H., Nishimura, M., Watanabe, H., Ueshima, A. et al., "Study on Similarity of Pumping Flow in Engine Crankcase," SAE Technical Paper 2009-32-0051, 2009, https://doi.org/10.4271/2009-32-0051.
Additional Details
Publisher
Published
Nov 3, 2009
Product Code
2009-32-0051
Content Type
Technical Paper
Language
English