Hi Bamelari,
To implement the "Less than Maximum Expansion" method in the supersonic nozzle design, your approach needs to be adjusted to account for the reflections and cancellations of expansion waves when the expansion angle is less than the maximum.
In a nozzle designed for less than maximum expansion, the initial expansion angle is set lower than what would be required for direct expansion to the desired Mach number. This means the flow needs additional adjustments, achieved through reflections.
Each reflection of the expansion waves further adjusts the flow properties, incrementally increasing the Mach number. The reflections act as additional expansion processes that help the flow reach the desired conditions.
Implementation steps:
1. Adjust Initial Expansion Angle: Modify the initial expansion angle to be less than the maximum. You can set it to a fraction of ThetaMax.
theta0 = (1.0/1.687)^(2/9) * (NuMax/2);
dT = theta0 / n;
2. Calculating Number of Reflections:
no_ref = ceil((ThetaMax - theta0) / dT);
3. Validation: Consider adding code for validation (e.g. checking if the exit Mach number is achieved)
if abs(exitMach - desiredExitMach) < 0.01
fprintf('Validation successful: The exit Mach number is within acceptable limits.\n');
else
fprintf('Validation failed: The exit Mach number is not within acceptable limits.\n');
By adjusting the code according to these steps, the "Less than Maximum Expansion" method can be implemented for the supersonic nozzle design.
I hope this helps.
