Another important simulation result is that no significant changes in HTCs have been found passing from the baseline configuration to the LHRE. This means that the convective hat transfer process remains unchanged by the increased wall temperature, because it strictly depends on the in-cylinder gas motion which remains unchanged.
However, as written in , the Flow model allows a more precise estimation of the spatial distribution of the heat fluxes, component thermal load and temperatures, addressing the complex LHRE issues.
Improvement in engine thermal efficiency can be reached with the so called Low Heat Rejection Engines (LHREs), in which the heat losses are reduced and utilized to increase the piston positive work, as well as to provide higher exhaust gas temperature for the downstream energy recovery systems.
LHREs are realized by covering the combustion chamber walls (pistons, liners, head, valves), the exhaust ports and manifold with insulating materials, called Thermal Barrier Coatings (TBCs).
Several simulation works have been carried out to estimate the performance, fuel consumption and emissions of the LHREs.