Paper Title
The Transient model of Two Phase Flow Heat Exchangers in N3-X Aircraft

This work presents modeling of two- phase flow heat exchangers to be used in modeling of NASA’s nextgeneration aircraft (N3- X). The heat exchanger model currently accommodates two working fluids; kerosene (jet fuel) and a refrigerant (R134a). The primary goal is to obtain a dynamic, robust model by using numerical simulation tools (MATLAB/ SIMULINK) which can simulate the system efficiently and would be used in the conceptual aircraft (N3-X) model. The final goal is to investigate the influence of pressure perturbation on the system. In other words, how quickly this system responds to change to perturbations, therefore the model will be transient. For this analysis, a sample time of 0.000001 seconds was used. Since, changing pressure suddenly from the higher value (650 kPa) to the lower value (555 kPa) is not a real, physical scenario in life, the pressure change with transfer function would be employed to transform the system into a first-order system with two different time constants. Eventually, the time constant of the system plays a significant role in obtaining a quicker response. Keywords - Two-phase flow, Heat exchanger, Pressure Perturbation, N3-X aircraft, Transient response.