Local heat flux measurement technique for internal combustion engines

The heat transfer from the combustion gases to the cylinder wall affects the efficiency, emissions and power output of an internal combustion engine. Measuring the heat transfer requires a heat flux sensor inside the combustion chamber that has a short response time and is able to withstand the harsh conditions during combustion. In this work, a suitable sensor is introduced and the measured wall temperature, heat flux and convection coefficient are compared to those measured with a commercial sensor. It was found that both sensors measure the same convection coefficient, but a different wall temperature and heat flux. This is because the presence of the sensor in the combustion chamber wall affects these quantities. A method is proposed to cancel this effect and calculate the actual heat flux through the cylinder wall.The heat transfer from the combustion gases to the cylinder wall affects the efficiency, emissions and power output of an internal combustion engine. Measuring the heat transfer requires a heat flux sensor inside the combustion chamber that has a short response time and is able to withstand the harsh conditions during combustion. In this work, a suitable sensor is introduced and the measured wall temperature, heat flux and convection coefficient are compared to those measured with a commercial sensor. It was found that both sensors measure the same convection coefficient, but a different wall temperature and heat flux. This is because the presence of the sensor in the combustion chamber wall affects these quantities. A method is proposed to cancel this effect and calculate the actual heat flux through the cylinder wall.C