how to deal with

michael

an inlet and outlet pipe on vertical wing of an aircraft.there is a heat exchanger within the pipe. the whole system is divided into three parts.first,the inlet pipe before heat exchanger,second, heat exchanger, third, the outlet after heat exchanger. now i only know the height 12km and mach number 2.3. so how to define the exit bondary conditons of the first part and heat exchanger, the inlet bondary conditions of the heat exchanger and the third part. how to deal with the heat exchanger, i only care pressure loss caused by it. any suggestions will be appreciated. sincerely, michael wwl