This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Improving Cylinder Cooling Using Tapered Fins and Baffle Plates between Fins in Air-Cooled Engines
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 12, 2010 by SAE International in United States
Annotation ability available
We aim to maximize the performance of air-cooled engines (such as motorbike engines and small stationary engines) by increasing cylinder cooling and by maintaining uniform temperature around the cylinder circumference. In typical engine designs, air cools the front of the cylinder better than the rear. In an effort to increase cooling at the rear, this research experiments with tapered fins that contract air flow to the cylinder axis between the fins, and with baffle plates mounted between fins symmetrically with respect to a plane through the axis of the cylinder. In a wind tunnel at air velocities between 20 and 60 km/h, we compared cylinders with conventional fins, cylinders with tapered fins, cylinders with baffle plates between conventional fins, and cylinders with baffle plates between tapered fins. We measured the temperature inside the cylinder to determine the heat release, and we measured the temperature on the fin surface to determine the temperature distribution around the cylinder circumference. We also visualized the air flow over the fin surface, using the oil film method, and between fins, using the smoke wire method, to understand how tapered fins and baffle plates contributed to cylinder cooling. Results indicate that both tapered fins and conventional fins with baffle plates between fins increased cylinder cooling, compared with conventional fins without baffle plates. Furthermore, our cylinder fitted with both tapered fins with the tapered portion closest to the rear, and baffle plates between fins, enjoyed the greatest cylinder cooling.
CitationNakashima, K., Teramoto, S., Murakami, Y., Ishihara, S. et al., "Improving Cylinder Cooling Using Tapered Fins and Baffle Plates between Fins in Air-Cooled Engines," SAE Technical Paper 2010-01-0323, 2010, https://doi.org/10.4271/2010-01-0323.
- Yoshida, M. Ishihara, S. Murakami, Y. Nakashima, K. Yamamoto, M. “Optimum Fin Layout of Air-Cooled Engine Cylinder in Air Stream,” SAE Technical Paper 2006-01-1229 SAE Transactions, Journal of Passenger Cars - Mechanical Systems: 1141 1149 2006
- Schey, O. Rollin, V. “The Effect of Baffles on the Temperature Distribution and Heat-Transfer Coefficients of Finned Cylinders,” NACA Report No.511 1936
- Brevoort, M. Rollin, V. “Air Flow around Finned Cylinders,” NACA Report No.555 1937
- Löhner, K. “Die Grundlagen der Luftkühlung der Brennkraftmaschinen,” MTZ 12 3 53 62 1951
- Stegemann, W. “Einïge Erörterungen über das Kühlungsproblem von luftgekühlten Motoren,” MTZ 12 3 63 69 1951
- Berndorfer, H. “Vorausberechnung des Kühlungsaufwandes von Motoren mit luftgekühlten Zylindern bei gegebener Verrippung und Luftführung,” MTZ 14 3 57 59 1953
- Radwan, M. Shahin, M. “The Effect of Cowling on the Local Cooling Effectiveness of Engine Air-Cooled Cylinders,” SAE Technical Paper 920790 1992
- Nakashima, K. Fujiyoshi, M. Ishihara, S. Murakami, Y. Yamamoto, M. Yoshida, M. “Cooling Effects of Air-Cooled Finned Cylinder Utilizing Contracted Flow,” SAE Technical Paper 2009-01-0176 2009
- Ishihara, S. Murakami, Y. Nakashima, K. Yamamoto, M. Yoshida, M. “Improvement of Cylinder Cooling in Air-Cooled Engine by Utilizing Baffle Plates,” SAE Technical Paper 2007-01-0546 2007