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Engine Design





For students enrolled in MAE3402 Design Project-Propulsion, feel free to use this page to u‍‍‍‍‍‍pload, share and analyse each others work ‍‍‍‍‍‍, make sure that you keep a copy of your work externally from here.

When you upload your work give it a heading and a brief summary of what its about and the conclusion from it, for example:

Just did more research on engines and i think we should go with ar731, its the same sized engine but is lighter, has the same power and has torque/power curves given which will help our analysis, also has the same fuel efficiency, see attached data file and write down your opinions please [|engine details] also these engines are like two strokes, what i mean is they burn oil so we need enough oil to run the thing as well as fuel amount is: 224cm ³ per hour at 6000 rpm (usage proportional to rpm)
 * Important:**

__**Body Interference**__ The interference of the fuselage, winds and any other structure behind or in front of the propeller blade has an effect of its efficiency and the amount of thrust the propeller is able to produce. I have found that even with a body with a diameter ratio of 0.7 to diameter of propeller the lose in efficiency is only 5% and it is actually better to have a blunt body directly behind the propeller close to the center because the effects of the propeller at the region are negative. Also the difference between a pusher and puller engine are that different with respect to body interference so either one is fine. The pusher has less propeller induced drag but lower thrust. for further information please see attached

Found this guys (probs seen it already), just more info on the engine that we were planning to use, including sketch with dimensioning and engine mount positions. dont know if it would be of any help or anything but thought id put it up anyway
 * __Engine Specs__**

Made a quick excel sheet (im not the best at excel) showing the fuel consumption based on different flight variables (speed, search duration, redundancies, power etc). Pretty rough but gets a good estimate based on BFSC and engine power output. Feel free to edit it and fix/add anything you want.
 * __Fuel Consumption__**

what kinda output are we gunna be needing? Tim: In the meeting last Friday the payload and electronics team were discussing the use of batteries for all electronic devices but they also advised that we should allow for use of any stock standard generator that comes with the AR741 because the batteries might be too heavy and not powerful enough or something.
 * __Generator?__**

I completed the same simple blade theory we went through in Propulsion using the same blade that Damon used as well, but down scaled it to diameters that are more appropriate for us. I scanned through my working on paper and the rest was completed in excel (also attached). The analysis I completed however didn't really allow the effect of hub radius so it might need to be altered slightly, but in the excel doc. you can also see that I did the analysis for a number of values. You can tinker around with the values yourself, the only values that you have to read from a graph are the gamma angle, which is highlighted in red, which also depends only on alpha (also highlighted in red). There are a number of gamma/alpha values in there with no real meaning, I just kept them there from past readings so that if any of the values were the same for alpha you could just read them directly. Enjoy
 * __Propeller analysis__**



__**Look at this**__ Jordan: Tutoring someone whos dad works at aerosonde, this is the prop off an RQ-7 shadow! What the fuck Jordan how on earth do you find these things? Gets some inside stats on it! or better bring us the prop and we will say we made it!

Just a little calc on determining the maximum static thrust for the propeller using fryade theory. Also used it to try to determine max power while moving but when using the calculation in this manner it doesn't work properly. Static thrust max is around 700N
 * __Fraude Theory__**

__Prop blade in CAD:__
I have been having a go at trying to CAD propeller blades in solidworks. Below are some files with my first attempts. There is a quick avi movie( use media player homecinema to open) and the corresponding solidworks part file ( Can't save it in NX format for some reason).The mfile takes airfoil coordinates in TEXT format ( as is usually the case from the net) and spits out a new TEXT file which can be directly imported into solidworks or NX. It also lets you scale the chord as desired ( airfoil coordinates from the web will be normalised to a chord of 1 m).Note that The Airfoil section is not for the NACA 4412 we are using, the twist was generated arbitrarily and the dimensions are not correct. Next step is to get the right airfoil coordinates and find a way to precisely input the twist.





**__Engine Selection__**
Heres the info for doing the engine selection part of the report

=Landing Gear project 2= Just in case I dont get back alive from day on the green, heres some stuff for landing gear. I am not sure if u can open solidworks assemblies in nx, let me know if not , and which format NX uses. I have included some layouts and Pardon the flimsy report, its almost 7am :s

Individual parts :




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