Heat Shield Insulation for Thermal Challenges in Automotive Exhaust System

While advanced automotive system assemblies contribute greater value to automobile safety, reliability, emission/noise performance and comfort, they are also generating higher temperatures that can reduce the functionality and reliability of the system over time. Thermal management and proper insulation are extremely important and highly demanding for the functioning of BSVI and RDE vehicles. Frugal engineering is mandatory to develop heat shield in the exhaust system with minimum heat loss. Heat shield design parameters such as insulation material type, insulation material composition, insulation thickness, insulation density, air gap thickness and outer layer material are studied for their influences on skin temperature using mathematical calculation, CFD simulation and measurement. Simulation results are comparable to that of the test results within 10% deviation. The performance index is calculated using the temperature gradient between the pipe surface and the external skin temperature. The performance index increases with material insulation thickness and insulation material density. Increase in insulation thickness from 6 mm to 19 mm reduces the skin temperature from 44% to 77%. The specialty insulation material provides a high performance index due to lower thermal conductivity. Overall heat protection of about 77% is achieved with optimal insulation thickness and material density.