SAE Aero Design Team Log - 2011 Competition Log
February 26, 2011
It's now been several weeks since we completed our design report. We're quite pleased with the final document; regardless of the score we get on it, it's a significant improvement from last year! But, we do expect to score highly, and not just relative to last year. Below is our payload prediction for our plane, generated from our MATLAB takeoff prediction script. If it proves to be as accurate as we hope it is, our plane should be very competitive this year.
Since our design report is out of the way, that means it's time to build! We just received the first shipment of build materials for the plane today, and the rest should be coming next week (we've had some minor setbacks in getting purchase orders submitted). Fortunately, next weekend (March 4-5) is Kettering's second Long Weekend of the term, so we're hoping to complete a large portion of the plane then.
Below is a screenshot of our final design.
With a rear wingspan of 10' and a front span of 8', this plane is considerably larger than last year's. Fortunately, we decided to make the rear wing 3-piece, and the front wing 2-piece, so shipping & transporting it shouldn't become a serious issue.
On another note, we're making good progress on getting the CNC machines assembled, so we should have those to help us with the build.
Wish us luck!
August 14, 2010
The design of our test plane is progressing, and only minor details will need to be modified before being built. Speaking of which, our purchase request for a CNC hot-wire foam cutter was approved! With any luck, we'll have it in a week or so, which means we need to buy some foam to build our test plane out of.
Our test plane is very unique in it's design. To give some background first, a tandem wing design has certain inherent difficulties in terms of aerodynamics. The turbulence coming off the rear of the front wing can cause problems with the rear wing - some sources have said this could be used to advantage, but most have stated otherwise. Because of this, and because we have no reliable access to either CFD or wind tunnel test data, we decided to make our test plane with variable parameters, primarily spacing between wings in both horizontal and vertical directions. This will allow us to determine the best relative placement between the front and rear wings, in order to maximize performance.
Below is a screenshot of our test plane design.
With any luck, we'll have enough time before the end of this term to build & fly this test plane - and get some useful results, too.
August 3, 2010
...And we're off!
Ok, so we started meeting several weeks ago. But we're starting to make some visible progress, including a decision on the configuration for our plane, as well as a design for a small-scale test plane.
The configuration we've chosen for our 2011 competition plane is a tandem design, based on the Scaled Composites Proteus and Draganfly Tango UAV.
Scaled Composites Proteus
Draganfly Tango UAV
The tandem wing configuration offers a number of potential benefits. First of all, as should be obvious, a tandem wing will offer more lift than a similarly-size monoplane, and smilar lift to a biplane. Second, having the lift more evenly distributed forward-and-aft on the plane gives it more stability than either a monoplane or biplane. This also gives us a little more leeway in determining the location of the CG. Last, but not least, it's just plain different. As far as we know, only one other SAE Aero Design team has attempted a similar configuration, at the 2010 Aero Design East competition. As any Aero Design team member likely knows, the judges like to see innovation, and we're hoping that the effort we put into this year's design qualifies as such.
In other news, we're still trying to obtain a home for the team. Last year's plane was built in the Auto Lab on the first floor of the Academic Building. Not only did we had to get Campus Saftey to unlock the room for us almost every time we wanted to work on the plane, we also had to be careful with all of our supplies & tools, since we were just borrowing a lab classroom that does get used for the occasional class. We have an ideal location in mind, an unused room with a lot of floor space and high ceilings, but the cost of putting in security doors for the adjacent HVAC room has kept administration from granting us access to that room. So, for the meantime, we're simply waiting it out, putting occasional pressure on school administration and hoping for the best.
It's late, so that's all for now... more to come later!