Large Eddy Simulation with dense fluid approximation and experimental study on the commercial diesel trans-critical injections

Diesel supercritical combustion can effectively improve engine efficiency and reduce harmful emissions. Therefore, studying the trans-critical injection characteristics of diesel is of great significance for further understanding of diesel supercritical combustion. In this work, a diesel trans-critical injection experiment is first carried out to test the liquid and vapor jet structure. Then the six-component surrogate of diesel is used to represent the thermo-physical properties of diesel in the range from subcritical state to supercritical state. Based on these thermo-physical properties, the dense fluid approximation method based on Large Eddy Simulation is applied to simulate the trans-critical injection processes of diesel. The results show that there is only a short continuous cold liquid core near the nozzle exit in the diesel trans-critical injection. The dense fluid approximation method based on diesel six-component surrogate and Large Eddy Simulation can accurately predict the diesel trans-critical injection properties. In order to accurately simulate the diesel trans-critical injection, it is necessary to develop a reliable diesel surrogate that can accurately emulate diesel various properties. Generally, this work is helpful to understand the characteristics of diesel trans-critical injections, and the numerical model is valuable for the optimal design of diesel engines.

Automated summary

Studying the trans-critical injection characteristics of diesel is essential for understanding diesel supercritical combustion, and the dense fluid approximation method combined with Large Eddy Simulation can accurately predict diesel trans-critical injection properties.