Experimental Investigation of the Impact of In-Cylinder Pressure Oscillations on Piston Heat Transfer

• Published in: SAE International journal of engines Vol. 9; no. 3; pp. 1958 - 1969
• Main Authors: Gingrich, Eric, Janecek, Daniel, Ghandhi, Jaal
• Format: Journal Article
• Language: English
• Published: Warrendale SAE International 03.10.2016; SAE International, a Pennsylvania Not-for Profit
• Subjects: Combustion; Cylinder heads; Cylinders; Data acquisition; Engine cylinders; Engines; Fuel combustion; Gas temperature; Heat flux; Heat transfer; Heat transfer coefficients; Ignition; Low temperature; Measurement; Pistons; Pressure oscillations; Properties; Telemetry; Thermal properties; Thermocouples
• ISSN: 1946-3936; 1946-3944; 1946-3944
• DOI: 10.4271/2016-01-9044

An experimental investigation was conducted to explore the impact in-cylinder pressure oscillations have on piston heat transfer. Two fast-response surface thermocouples embedded in the piston top measured transient temperature and a commercial wireless telemetry system was used to transmit thermocouple signals from the moving piston. Measurements were made in a light-duty single-cylinder research engine operated under low temperature combustion regimes including Homogeneous Charge Compression Ignition (HCCI) and Reactivity Controlled Compression Ignition (RCCI) and Conventional Diesel (CDC). The HCCI data showed a correlated trend of higher heat transfer with increased pressure oscillation strength, while the RCCI and CDC data did not. An extensive HCCI data set was acquired. The heat transfer rate - when corrected for differences in cylinder pressure and gas temperature - was found to positively correlate with increased pressure oscillations. It is important to normalize the data before drawing conclusions as the magnitude of the effect was diminished significantly by the normalization procedure.