Internal Combustion Engine: Input.speed

[Cameron Shellard]

Hello, 

I am working through some kinks in my internal combustion network and converter. 

In the "Converters\Internal_Combustion_Engine.py" file, the 'self.inputs.speed' variable [units = RPM] is being set to the default value of zero (this results in my output torque being infinity).

I have been unable to find how to define this input without altering 'speed' in the '__default__' function (not ideal). I am unsure how or where to assign it? or if I am just misunderstanding how it fits into the network.  

If you require any additional information just let me know.

Any help would be appreciated and Thank You in advance.

Kind regards,

Cameron

[ebot...@gmail.com]

Hi Cameron,

This the rotational speed (RPM), which is an input to the engine. Usually it is a vector of values for each point in a mission.

A good example of how we use the engine model is in the constant speed speed internal combustion network. A constant speed propeller has mechanism to adjust the pitch of the blades to hold a fixed RPM. You can read about them more here. For that network, the pilot (or in our case the designer) fixes the RPM for the mission segment. The engine is still throttled. The intention of this is to work like a transmission of a car.

With a fixed pitch propeller, throttle is the only control variable. So the power generated by the engine must equal that which the propeller produces. This requires an extra unknown (speed) to converge the torque from the engine and the propeller to be the same. So that network is a little more complicated, even if mechanically it is simpler.

I'm not sure what your use case is. But hopefully that helps you understand how internal combustion engines work.

-Emilio