A high-speed transient surface temperature sensor was designed and manufactured with two key features that differentiate it from other sensors. First, the sensor was designed such that 1-D conduction can be unambiguously assumed. Second, the sensing element was placed on top of a thermal amplification layer that increased the temperature swing experienced by the sensing element. This increases the signal without an increase in the noise. The sensor was manufactured using both lithographic and aerosol jet printing techniques. The lithographic manufacturing technique was much more difficult and had a far lower success rate than the aerosol jet printing technique. Both sensor types were tested in a motored internal combustion engine and a shock tube to characterize their performance. The sensors were found to be more than capable of crank angle resolved temperature and heat flux measurements of a combustion engine cylinder wall. They had a significantly better signal-to-noise ratio than alternative surface temperature sensors. Both sensors measured a near-vertical step change in heat flux induced by a passing shock. The aerosol jet print sensor was found to have performance comparable to that of the lithographic sensor, albeit at a higher Joule heating rate than the lithographic sensor. Overall, Joule heating was found to be negligible compared to the measured heat flux magnitude.
The thermal loading of a pre-chamber wall was also tested using a standard thermocouple. A custom pre-chamber was designed and built to accommodate a thermocouple in the wall between the cylinder and the pre-chamber. The resulting temperature measurements showed that the pre-chamber wall reaches a temperature much higher than typical engine components, up to 424 °C. Transient data revealed the pre-chamber wall responded quickly to changes in
engine conditions.