How Time Flys

It has been a while since last I posted. This post is late because I just got home and decided to post before passing out. A couple of weeks ago me and some friends went to a airplane museum in southern jersey. It is the Air Victory Museum you may recall that we have visited in the past as can be seen here. This trip however there where a few changes, for one thing I have not cut my hair since the last visit, and for all intents and purposes I have also not trimmed my beard. Have fun.

This is of course me standing in the cockpit of a F-14 Tomcat.

This is from a little more than year ago.

And this is from now.

Once again from a year ago.

And this of course is from now. Kunal looks exactly the same, he even is wearing the same hat.

I'm Back

Well after a long break from posting I am back. In the past couple of years I have often spoken of the AIAA and how we design and build an airplane. Well I have finally bought an airplane of my own.It is about three feet long, and powered by two ducted fans. I have to slightly modify the front landing gear so that it tracks straight and then flying time. I will post pictures and videos of course (assuming someone is there to do it for me, I will be flying after all).

Experimental Fluids

Last week I did not post because of today's post. Now I know this seems kind of silly, however this post will explain. Last week I was working on my final project for my Graduate Experimental Fluids class. It consisted of placing a model of the AIAA clubs airplane in a water tunnel. This year the Rutgers AIAA club is building an autonomous UAV that has a camera in the nose, because of the camera a ball turret is going to make up the front of the nose. We wanted to see how much this effected the flow, and to look at the vortex shedding from the ball.

This is the 3/4 scale model of the front section of the aircraft, the design has changed a bit since the model was initial built. However, the model took around 100 hours to build in a FDM (fused deposition modeling) rapid prototyping machine, so we did not have time to make another (also the model was screwed up 3 times due to power failure, one of which I spoke of here and here).

This is the entire set up as we ran the experiment. The experimental method we used is called PIV (Particle Image Velocimetry). It consists of a laser (green square, class 4 laser running at around 125-145 mJ and 532 nanometers wavelength) that is run through a series of optics (light blue square, spherical and cylindrical lenses) that makes the into a thin sheet. Then a mirror (yellow square) reflects the laser sheet around the model and a camera (red square, CCD camera) takes two pictures very close to each other timed to coincide with the lasers pulses with a time difference of in our case 2500-6000 microseconds so around 2.5-6 Milli seconds. The two pictures show illuminated seed particles (in this case I believe we where using glass beads, with a diameter of around 4 microns). Then computer software compares the two images and based upon where the particles moved to it creates a plot of the vector field, and vorticity.

This is the model as it looks before we had to invert it to get it in the right place with regards to the laser sheet.
This is what the whole set up looks like from the top, the only thing I haven't mentioned is the sychronizer, which synchronized the laser and the camera.This is the kind of vector field you get, in this case it is the mean velocity field from 50 individual vector fields. Note the stagnation point at 1.5 inches on the bottom axis (a stagnation point is a point where the flow speed is zero).
In the mean velocity plot for the 15 Hz pump speed the flow is moving a lot slower and as a result the stagnation point is now much farther to the right at pretty much the edge of the image. Also, there are two distinct vortexes (see if you can find them, one is a lot easier than the other. Hint: the shear layer/boundary layer propagates from where the flow separates from the sphere of shot to the left to the fuselage on the right) this indicates that for the slow flow there is a steady state solution.
This is what one of the instantaneous velocity fields looks like, there where 50 of these to make the average field in the image above. You can see a vortex in the approximately the same place as in the mean velocity plot and its pair.
Sorry there is no scale on this graph, also sorry about it not being bounded properly. At (0.75, 1.4) and at (1.25, 1) there is a clear vortex pair. A vortex pair consist of two counter rotating vortexes (see this animation).

Now you can see what I was talking about not posting last week, so this is just a post worthy of two weeks. To give you an idea, the experiment took two people (me and my friend Andrew) around 30 hours a piece to set up (after the model was made) and around an hour to take the data, such is the way experiments work. Hopefully we will be able to do more tests, looking at different sections of the flow, and trying to stop the vortex shedding, as it produces a ton of drag.

Flying

Over the past two years I have talked about the AIAA and the planes we built for it. Well we have finally finished our first plane. It is a year late, but it is the first plane the current members of the club ever designed. I worked on the construction and design of ever element of the plane except for the wings, and now I am proud to say it has flow.

More Fun With Airplanes

Last week me and some friends volunteered at a airplane museum in southern New Jersey. This basically meant that we could go where u can't normally go and touch what you can't normally touch, while we cleaned everything. Here are some pictures.

This is me standing on a F-14

Propeller on an E-2 Hawkeye

Me sticking my head out of the cockpit of an E-2, it was really cool I just had to pull open the hatch on the top of the cockpit.

In the cockpit of the E-2

This is the set up in the back of the E-2

F-4 phantom

This is what is inside and F-4 Phantoms cockpit

The museum is located on an airfield, and this was a bulletin board in the main building for the airport.

Just for fun

Finishing with a what the heck is that thing, we passed this right after we left the museum. An guesses as to what it is?

Aero Antics

Over winter break me and some friends went to DC for two days. In two days we toured two air and space museums, fun. Did I mention we are all members of the AIAA club at Rutgers.

The group I went with, (left to right) Mysterious Black Rectangle (The person in question requested that no picture or name be posted on the internet) Jared, Me, Curran, Pasha, Jimmy, Sergey, Andrew

Pasha and Me with Space Ship One.
The Soviet moon suit design.
The life support system on the Soviet moon suit, notice the piece of wood.

This is me taking a picture of the Capitol building and friends, it just happened that Pasha was taking a picture of the Washington monument. As luck would have it he got this picture.

RC Engine

Well I took apart and cleaned the engine that was used on the AIAA plane from last year’s competition. I have also built a wheeled system to mount the engine on (also will be used to break in the new engine), I call it the poodle (not sure why, I just do).

This little guy gets a decent amount of thrust so we had to tie it to the table behind it so it couldn't run away.

Sorry about the video quality I took it on a digital camera.

Plane Building

I haven’t given an update on AIAA building progress recently. Unfortunately, the rate of our building has been a bit slower than expected. We have completed the main frame, the main shaping fuselage foam, and the nose cone. We have completed the design, and are not on the final legs of the build, at this point there is no more design work involved we are not working almost primarily on building. I do not have any pictures of the actual constructed plane however here is a CAD (Computer Aided Drawing) model of the plane now (I CAD’ed the tail frame however it is covered by foam shape of the tail, additionally the tail is not yet finalized, almost).

AIAA Update

Well the AIAA didn’t go to the plane competition this year, this was due to a combination of the fact that we basically ran out of time, we couldn’t fund the transportation costs to get to Texas, and the competition was in the middle of our exams. Regardless of this, we decided to proceed with the construction of the plane; the purpose of this was for the club members to gain construction experience, and so that we could test the design to see what we would want to change for next years plane. Additionally, we can use this year’s plane as a test platform for next years design changes. Besides overseeing all the construction for this years plane my project over the past couple of days has been how to mount the tail control surfaces to tail boom. On Friday I came up with a design, we discussed and then modified the design. Yesterday I cut out a test piece; from this piece I realized that I had to slightly modify my dimensions. So, I went back to the computer and fixed up my CAD drawing. Today I completed the part, it took me about three hours to do it, this included sketching the part on a piece of sheet metal then cutting it out with a band saw and finally with a hammer beating out the final piece. I don’t have a picture of it with me, so I will post the 2D expanded CAD view of the part.

Rocket Mayhem

They say a picture is worth a thousand words, but I always felt that this depended upon how many words you really wanted to write about the picture. However, I do think that what I am holding says all the words it needs to. It is in fact a small, totally home made rocket; this includes the propellant which I made. The fuel is Potassium Nitrate (KNO3, Saltpeter), and table sugar (there are trace elements of Carbon and Sulfur). This may surprise you that the rockets propellant is made out of sugar and fertilizer however this is a very well documented amateur rocket propellant (sometimes called Candy Propellant). Anyways I mixed the dry powder with some alcohol and using a rod to maintain a hollow core to the engine; I packed the mixture down with another rod and let it dry. I then put a nose cone on it and installed a fuse and the wooden stick that gives it stability in flight. Then it was put on our launch rod and prepared to be fired; I lit the fuse and ran. You can see the length of the fuse in the picture and it wasn’t long enough so I didn’t actually see it go up. But the other observers say it went well over the tree line so I figure maybe 100-150 ft for my first ever rocket engine I was very happy. We tested other rockets that day with varying success. One rocket started to thrust, flew about 8 ft in the air and fell back down having run out of thrust (this was due to poor packing of the fuel, in this case black powder). The other rocket had an experimental nozzle on it, however this just resulted in pressure building up until the nozzle blew out, and the rocket got tilted when this happened; the result a rocket streaking across my backyard at about a 45 degree angle to the ground. The ultimate purpose of these activities is to start a rocket group within the Rutgers AIAA club. However, the people I did these activities with asked to be not named, because of this I cannot post the video we took until I have had time to edit them. However you have something to look forward to.

Launch Control, if you look in front of me you will see the rod with the rocket on it even though it camouflages with my shorts.

Launch Control by the end of the day, you can see the scorched ground below the laucnh rod. Also, you can see some of the sticky sugar from the fuel stuck to the rod. I would like to make sure it is clear that we had my mothers permission to do this, and she watched on all our launchs.

These are four more engines I have made since that day. The two on the left are black powder, the one second from right is mostly sugar fuel with a bit of black powder (I ran out of sugar fuel) and the one on the right is all sugar fuel.

PLEASE NOTE THAT THOSE WHO PARTICIPATED IN THE CONSTRUCTION AND LAUNCH OF THESE DEVICES WHERE VERY CAREFULL. THIS SHOULD NOT BE ATTEMPTED BY PEOPLE WHO DO NOT UNDERSTAND THE DANGER OF WHAT THEY ARE WORKING WITH. THESE ACTIVITIES SHOULD NEVER BE UNDERTAKEN WITHOUT ADULT SUPERVISION.

Look Out Below

I have in the past on numerous occasions mentioned the AIAA such as here, here and here, this post will be no exception. Last year I won both the Build your own airplane competitions (as you can see the linked posts I did blog about them). Last Thursday we had yet another build your own airplane competition (I missed the one last semester do to a wedding), because I am the Co-Design Team Leader I could not actual compete so I decided to have a bit of fun. In other words I played around outside of the constraints of such things as rules. Here are all the pictures from the competition that I posted on Facebook. This is a video we found of last years plane actually in motion the person who runs out to get the plane is my friend Sergey. Finaly this is the article that was front page news in The Daily Targum (look for my quote).

This is the picture of the winning plane.

This is my plane, just a little bit bigger than the other ones (just for my wing I used twice the material they got)

They aimed for the sky, and missed

In previous posts (here and here) I mentioned one of the clubs I am in was making an airplane. Well we finished it and it went down to GA to compete. To cut out a whole lot of technical aerospace jargon I will put it simply: the plane won the record for most propellers destroyed and most crashes survived. Basically the servos that powered the controlling surfaces (flaps/ailerons, rudder, and elevators) had about a 1/5 of the power they needed. When the plane got to about 30 mph the pilot attempted to take off, the wind overtook the servos and the plane pitched into the ground. This happened about 15 times, until they cut down the elevator to about a third of its original surface area and got it into the air. However the center of gravity was above the fuselage and the plane started swinging around (very amusing video they have of it). Then it crashed and the rudder section broke off, and the front landing gear bent. It's still fixable, so some friends and me are going to fix I up and make it fly.
Here are some pictures for your viewing pleasure.

OOPS!!!

Houston we have lift off!

Yeah!

See it did actualy fly in the end.

So ended the build a plane odyssey for this years graduating seniors.

Aiplanes and Corrections

In the past I mentioned a club that I was in called the AIAA. In this previous post I talked about how I won a build your own airplane competition. Now the club is building a real airplane, it is a biplane with each wing being just short of 8 feet. I helped build and it is rather cool. Here are the current pictures of the plane.

I must also thank notelon for his informing me of my calculation error in last weeks post. Each student only gets 200 megabytes not 100 gigabytes this changes all the numbers by three orders of magnitudes.

Here is the text of his email telling me this (Colonel Henry is the name they give the answer this email address at Rutgers)

Question:
What is the maximum number of megabytes of space available per Eden Account?
Answer:
Hi,
Students are allowed a total space of: 200MB
Thank you for emailing Colonel Henry

This is the picture that made me think that Rutgers gave us 100 gigabytes.

MAYDAY MAYDAY !!!!!

Last semester I entered a "Build Your Own Plane" competition with Yoni and some grad student named Sergey. We won the competition. Last Thursday, the AIAA (American Institute of Aerospace and Aeronautics) Club (of which I am a member) held a second "Build Your Own Plane" competition. This time I entered with one of my fellow freshman engineers, Pavel. After the last competition, people complained about a post-doc winning first place, so I had to prove that it wasn’t all him this time.
This time we had to build a glider, so I came up with a long thin wing design. The Targum (Rutgers Newspaper) was covering the competition [registration may be required]. So we built our plane and tested it, made some alterations, and then completed the plane we dubbed the U² because it looked like the U2 spy plane. We went to the flight range (a classroom in the engineering building) and started the competition.
Sadly most planes didn’t actually fly, others did but had a high stall speed, and most that actually flew hit the ground at the bottom of the room. Then it was our turn, I threw it first and it hit the ceiling, then Pavel threw it and it glided gracefully across the room hitting the wall very high up, the third run did the same but the long way of the room. With the first messed up flight we still had a total flight time of 10.7 seconds of flight hindered very much by the fact that it kept hitting the walls 2/3 of the way up. We won.

Here is a picture of the two planes that my teams built and that both won first place in the AIAA display case. (the tails are removed to get them into the case)

(The smaller one top left is the first, the bigger one with the U² on it is the recent one)

Here is a picture from the Targum of my plane flying.
And of course here is the link to the actual article.
University Engineers Aim For The Sky
(registration may be required but shouldn't be)