Transport Flights Validation

[Conor Gallagher]

Hi SUAVE Team, 

I'm doing a PhD under Ryanair's Sustainable Aviation Research Centre. As part of my research, I have decided to use SUAVE as my modelling tool, and so I am currently trying to validate SUAVE's fuel flow output using a range of flight data that I have access to. 

For this validation, I want to incorporate wind velocity and essentially create two missions for my flight analysis. True airspeed would be used for fuel-flow calculations, whereas ground speed would be used to compute flight time/range. 

I am curious as to how I might go about this? If you think it would be useful, I would be happy to develop the SUAVE code to add in this functionality, in case future users wish to perform similar detailed validations. 

I see that there is a wind frame in files such as Frames.py and Aerodynamics.py. But this is just a frame of reference rather than actually affecting the relative wind vectors, if I have interpreted correctly?

For methodology, I was thinking I could either create two missions and then call the appropriate mission to each analyses class (Energy, Aerodynamics etc.)

Or else I could develop new segment options in the mission analysis, where wind velocity would be an optional parameter to add to your cruise segment, for example.

Any input would be appreciated, thanks in advance.

Conor 

[Emilio]

Hi Conor,

You're correct, the wind frame has to do with frames of reference for stability. What you need to track is the relative motion of the vehicle to the ground. Basically you need to update some of the functions here. The inertial position and planet position is zero wind. Those are all post process steps after solving.

SUAVE does have a true course of the vehicle as well as a heading. So make sure those are factored in.

Feel free to continue asking questions. I'm looking forward to a pull request.

Thanks,

Emilio

[Conor Gallagher]

Hi Emilio,

Sounds good, thanks for pointing me in the right direction. I'll have a look at this in the coming days and I'm sure I'll be back with a few questions later - still getting used to SUAVE and python in general. 

Cheers,

Conor

[Conor Gallagher]

Hi Emilio,

Sorry, I've only got round to looking at this in the past couple of days.

At the moment, I have a working wind_speed parameter added to the constant_speed_constant_altitude cruise segment. A ground speed is calculated and used to calculate the flight time, and these values are then packed and brought over to the Frames.py file and used in the update_planet_position and integrate_inertial_horizontal_position. 

The wind speed is just a scalar value at the moment, which is then input as the x-component of a new parameter wind_velocity_vector (I've just followed the methodology for air_speed). 

So basically you can only define a headwind/tailwind in the standard cruise segment for the moment, so aircraft heading is not affected. By the way, where is the heading defined? I couldn't find it.

Maybe there's a better way to do this - let me know what you think, or if I've done anything wrong here. 

I'd eventually like to have an optional 3D vector input, and also add this functionality into climb/descent segments. 

Kind regards,

Conor

[Emilio]

Hi Conor,

The heading angle is defined in the frames. It's not intuitive, we have a PSI angle. In the past I've manually changed that such as in the Solar UAV Optimization tutorial.

Recently we added a True Course as well to the missions for noise analysis but this isn't well integrated.

-Emilio