How does thruster file Direct work.

[prashant19012002]

For example wkt if Ct and Cp of a propeller is mentioned wrt to advance ratio then JSBSim calculates the thrust for any conditions based on this values. But how does the file direct work .

[seanmcleod]

The Direct option is used as the comment mentions for engine types that compute the thrust, e.g. a gas turbine engine like this one in the 737 model, i.e. there is no propeller that takes the power and torque from the engine to then produce the thrust.

jsbsim/aircraft/737/737.xml

Lines 124 to 140 in ae4652a

	<propulsion>
	<engine file="CFM56">
	<feed>0</feed>
	<feed>2</feed>
	<thruster file="direct">
	<location unit="IN">
	<x> 540 </x>
	<y> -193 </y>
	<z> -40 </z>
	</location>
	<orient unit="DEG">
	<roll> 0 </roll>
	<pitch> 0 </pitch>
	<yaw> 0 </yaw>
	</orient>
	</thruster>
	</engine>

P.S
Rather than posting screenshots for your examples above, rather paste them inside a triple back tick set marked as xml. That way the text is searchable in future etc.

[prashant19012002]

I saw the engine file CFM56 since its a turbine engine the trust values are mentioned based on density altitude and mach no. .
But can i know how do we modify it for electric UAV as in this example of x8 UAV .

`

<electric_engine name="electric">

8.0
</electric_engine>`

I tried to run this x8 plane with some cruise scripts and i could do this and achieve trim based on your discussions in thread #853 . Now i wanted to replicate the same thing in for my electric motor propeller combo (but instead of a separate propeller i wanted to mention thrust directly).
The main reason for doing this is for some reason i am not able to start my engine in normal case where i mention propeller and engine file.