In-Cylinder Heat Transfer Determination Using Impulse Response Method with a Two-Dimensional Characterization of the Eroding Surface Thermocouple Univ of Malta

Format:

Book

Conference/Event

Author/Creator:

Caruana, Carl, author.

Contributor:

Farrugia, Mario

Mollicone, Pierluigi

Pipitone, Emiliano

Sammut, Gilbert

Conference Name:

15th International Conference on Engines & Vehicles (2021-09-12 : Capri, Italy)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2021

Summary:

Heat transfer from the cylinder of internal combustion engines has been studied for several decades, both in motored and fired configurations. Its understanding remains fundamental to the optimization of engine structures and sub-systems due to its direct effect on reliability, thermal efficiency and gaseous emissions. Experimental measurements are usually conducted using fast response surface thermometers, which are able to give the cylinder surface temperature fluctuation as well as the mean. The transient component of heat flux through the cylinder wall was traditionally obtained from a spectral analysis of the surface temperature fluctuation, whereas the steady-state component obtained from Fourier's law of conduction. This computation inherently assumes that heat flows in one-dimension and perpendicular to the heated surface in a semi-infinite solid with constant thermo-physical properties. Results obtained are known to be prone to significant uncertainties originating from numerous sources, most of which related to the limitations in the technology of surface thermometry, as well as the method used to convert the surface temperature to heat flux. In this study, a single cylinder version of a 2.0 liter engine operating in the pressurized motored configuration was instrumented at two locations in the cylinder head with surface thermocouples of the eroding type, one fitted along the cylinder central axis and another in the squish region. The processing of the surface temperature signal into heat flux was conducted using the Impulse Response method, coupled with a two-dimensional finite element model that was done to characterize the heat transfer behavior of three different eroding surface thermocouples that were tested on the experimental setup. This method is aimed at partially solving the problem of inaccurate heat transfer determination originating from the traditional, unrepresentative, one-dimensional assumption. In this proposed publication, the implemented method of obtaining the in-cylinder heat transfer from the measured surface temperature is presented

Notes:

Vendor supplied data

Publisher Number:

2021-24-0018

Access Restriction:

Restricted for use by site license