Which of the following assumptions /conditions are true in the case of Rayleigh flow?
1. Perfect gas.
2. Constant area duct.
3. Steady one-dimensional real flow.
4. Heat transfer during the flow.
Select the correct answer using the code given below:
a. 1,2 and 3 b. 2,3 and 4
c. 1, 3 and 4 d. 1, 2 and 4