Turbulence and Cycle-by-Cycle Variation of Mean Velocity Generated by Swirl and Tumble Flow and Their Effects on Combustion 950813
Combinations of swirl flow and tumble flow generated by 13 types of swirl control valve were tested by using both impulse steady flow rig and LDV. Comparison between the steady flow characteristics and the result of LDV measurement under motoring condition shows that tumble flow generates turbulence in combustion chamber more effectively than swirl flow does, and that swirling motion reduces the cycle by cycle variation of mean velocity in combustion chamber which tends to be generated by tumbling motion.
Performance tests are also carried out under the condition of homogeneous charge. Tumble flow promotes the combustion speed more strongly than expected from its turbulence intensity measured by LDV. It is also shown that lean limit air fuel ratio does not have a strong relation with cycle variation of mean velocity but with turbulence intensity.
Citation: Urushihara, T., Murayama, T., Takagi, Y., and Lee, K., "Turbulence and Cycle-by-Cycle Variation of Mean Velocity Generated by Swirl and Tumble Flow and Their Effects on Combustion," SAE Technical Paper 950813, 1995, https://doi.org/10.4271/950813. Download Citation
Tomonori Urushihara, Taichi Murayama, Yasuo Takagi, Ki-Hyung Lee
Nissan Motor Co., Ltd., Han Yang Univ.
International Congress & Exposition
Applications and Developments in New Engine Design and Components-SP-1071, SAE 1995 Transactions: Journal of Engines-V104-3