To achieve high power density and thermodynamic cycle efficiency, the working pressures of liquidpropellant rocket engines, diesel engines, and gas turbines (based on deflagration or detonation) are continuously increasing, which could reach or go beyond the thermodynamic critical pressure of the liquid propellant. For this reason, the studies of trans and supercritical injection are getting more and more attention. However, the simulation of transcritical phase change is still a challenging topic. The phase boundary, especially near the mixture critical point, needs to be accurately determined to investigate the multicomponent effects on transcritical injection and atomization. This work used our previously developed thermodynamic model based on the vaporliquid equilibrium (VLE) theory, which can predict the phase separation near the mixture critical point. An \textit{in situ} adaptive tabulation (ISAT) method was developed to accelerate the computationally expensive multicomponent VLE computation such that it can be cheap enough for CFD. The new thermodynamic model was integrated into OpenFOAM to develop a VLEbased CFD solver. In this work, shockdroplet interaction and twophase mixing simulations are conducted using our new VLEbased CFD solver. The shockdroplet interaction simulation results capture the thermodynamic condition of the surface entering the supercritical state after shock passes through. The atomization of droplets could be triggered by vorticity formed at the droplets' surface. 2D temporal mixing layer simulations show the evolution of the transcritical mixing layer and capture the phase split effect at the mixing layer.
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Investigation of transcritical shockdroplet interaction using vaporliquid equilibrium (VLE)based CFD simulation
To achieve high performance, the working pressure of liquidfueled rocket engines, diesel engines, and gas turbines (based on deflagration or detonation) is continuously increasing, which could reach the thermodynamic critical pressure of the liquid fuel. For this reason, the studies of trans and supercritical injection are getting more attention. However, most of the multiphase researches were mainly concentrated on single or twocomponent systems, which cannot capture the multicomponent phase change in real highpressure engines and gas turbines. The phase boundary, especially near the critical points, needs to be accurately determined to investigate the multicomponent effects in transcritical flow. This work used our previously developed thermodynamic model based on the vaporliquid equilibrium (VLE) theory, which can predict the phase separation near the critical points. An in situ adaptive tabulation (ISAT) method was developed to accelerate the computation of the VLE model such that the expensive multicomponent VLE calculation can be cheap enough for CFD. The new thermodynamic model was integrated into OpenFOAM to build a VLEbased CFD solver. In this work, simulations are conducted using our new VLEbased CFD solver to reveal the phase change effects in transcritical flow. Specifically, shockdroplet interaction are investigated to reveal the shockdriven high pressure phase change.
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 Award ID(s):
 2023932
 NSFPAR ID:
 10348734
 Date Published:
 Journal Name:
 ILASSAmericas 32nd Annual Conference on Liquid Atomization and Spray Systems
 Page Range / eLocation ID:
 13
 Format(s):
 Medium: X
 Sponsoring Org:
 National Science Foundation
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