Numerical simulation of trans-/near-/supercritical injection characteristics based on real fluid properties

Abstract

In this paper, the trans-/near-/supercritical jet models were established using a combination of large eddy numerical simulations and real fluid equations of state (EOS) in order to systematically investigate the heat and mass transfer mixing process of the jet at supercritical pressure. The effects of EOS, injection temperature (Tinj), ambient pressure (Pamb), and the pseudo-boiling phenomena on the density field, temperature increase rate, spray penetration, spray area, spreading angle, and mixing layer thickness of the spray were investigated. The results reveal that the initial shape of the spray is connected to its thermodynamic and transport characteristics. The correctness of fuel characteristic parameters impacts the development of the jet. For trans-/near-critical sprays, the temperature rise rate, spreading angle, spray area, and mixing layer thickness are enhanced, indicating the mixing efficiency is improved by increasing the Pamb and Tinj. However, raising the Pamb has a detrimental impact if both the Tinj and the Pamb exceed the critical parameters. This is owing to the link between Tinj and pseudo-boiling temperature, which results in a trade-off between Pamb and the objects discussed above for supercritical sprays. This research is essential to comprehend the heat and mass transfer mixing process of the supercritical jet.