UNIVERSITY OF NORTH DAKOTA FROZEN FURY NASA STUDENT LAUNCH INITIATIVE POST-LAUNCH ASSESSMENT REVIEW MAY 13, 2014

Transcription

1 1 UNIVERSITY OF NORTH DAKOTA FROZEN FURY NASA STUDENT LAUNCH INITIATIVE POST-LAUNCH ASSESSMENT REVIEW MAY 13, 2014

2 2 Table of Contents Team Name 3 Motor Used 3 Brief Payload Description 3 Rocket Height 5 Rocket Diameter 5 Rocket Mass 5 Altitude Reached 5 Vehicle Summary 7 Data Analysis & Results of Vehicle 9 Payload Summary 10 Data Analysis & Results of Payload 12 Scientific Value 13 Visual Data Observed 13 Lessons Learned 15 Summary of Experience 16 Educational Engagement Summary 16 Budget Summary 17

3 3 Team Name University of North Dakota Frozen Fury Rocket Team Motor Used Aerotech L850W Information about the Motor: o Casing: RMS 75/3840 o Class: 26-50% L o Diameter: mm o Formula: White Lightning o Length: mm o Letter: L o Propellant: APCP o Type: Reloadable o Designation: L850W o Delays: Plugged o Propellant Weight: g o Total Weight: g o Average Thrust: lbs o Peak Thrust: lbs o Total Impulse: Ns o Class: 44% L o Thrust Duration: s Brief Payload Description o Hazard Detection Camera: The Hazard Detection Payload consists of a camera and the necessary electronics to scan the ground during decent. The camera is located in the nose cone, and will be able to view outside of the rocket, with the use of the Faring System, after the drogue parachute is deployed. As the rocket is descending, the camera will take pictures of the ground every 15 seconds, and process the images on board the rocket. As the images are processed, the software will detect any hazards on the images. This information will be sent to a ground station. Right: A picture of the antennas for the rocket and ground station.

4 4 o Faring system: The faring system is designed to expose the hazard detection camera to the outside environment. This system is entirely mechanical and consists of few moving parts. The system draws the needed force from the deployment of the drogue parachute. It will do this through a simple system consisting of a tether running from the chute to two pulleys; the tether is then attached to a rod. Upon the deployment of the drogue parachute, the force from the air resistance will cause the rod to push the nosecone up 1.5 inches; this will then allow the segmented cylinder housing the hazard detection camera to separate. The four segments will be attached to the body tube by locking hinges so; when the segments separate they will be folded back towards the body tube and away from the nose cone, revealing the hazard detection camera. Right: A picture a model of the faring system, displayed at the rocket fair. Below: A diagram of the fairing system within the rocket. o Liquid Sloshing Payload: The Liquid Sloshing payload comprises of two tanks, one cylinder and one rectangular prism, each partly filled with colored water. Each tank is divided into two parts, one is the control tank, and the other will contain a baffle. The

5 5 perforated disc baffles are intuitively installed one quarter of the way in the tank, since half of the tank is the control. The design essentially reduces amount of space available for the free surface of fluid to move. The perforated discs, hopefully, will damp out the fluid movement, and we will compare the results gathered between the 2 different tanks. Each baffle contains 5 holes, in an X-like pattern. With one in each corner (total four, and the fifth in the middle. The fluid movement during the rocket flight will be recorded on a Hero 3 Go Pro camera to be used for further investigations. The tanks are fabricated from Plexiglas the parts being held by epoxy. The entire payload weighs about 3 lbs. Right: The sloshing payload tanks with the camera. This payload is intended to provide information that can give insight into the effect of sloshing of rocket fuel as it is depleted during flight. The perforated disc pattern has been selected because it is the easy to fabricate and could substitute for in-flight adjustable baffle system. Rocket Height Length: in. or ft. Rocket Diameter Diameter: 6.0 in Diameter Span: 19.0 in Rocket Mass Loaded Mass (without liquid payload): oz. or lbs. Total Mass oz. or lbs. Altitude Reached Altitude: 5419 ft

6 6 For our flight, we used two Perfect Flight StratoLogger Altimeters. Our primary altimeter was set to deploy the drogue parachute at apogee and the main parachute at 700 ft. For our back up altimeter, we set the drogue parachute to deploy 1 second after apogee and the main parachute at 600 ft. Right Top: Data obtained from our primary altimeter, A. Below Left: Data obtained from our back up altimeter, B. We believe the spike came from our back up charge for the Main parachute. It was recommended to us to use a 4-gram charge of 4F black powder. This appeared too large, and caused the violent spike in the data. Below Right: This graphical data comes from our back up altimeter, B, with the violent spike removed. What we learned from both altimeters and video analysis of the launch is that the Main parachute deployed 7 10 seconds after apogee. We believed this is due to the over charged back up charge for the drogue parachute. For our previous flights, we had a primary and back up charge of 4.25 grams of 3F black powder. During our LRR, it was requested that we change our back up charge to a larger amount. Since the cups used to contain the black powder charges would not hold more than 5 grams, we used 4F black

7 7 powder. Because of this early than expected deployment, our rocket did drift about 1 mile further away. Below Left: A picture of our rocket descending after reaching apogee. Below Right: the main parachute (red and white) deployed shortly after the drogue parachute (green). Vehicle Summary Right: Fully assembled rocket. The following are descriptions of the sections and parts of the vehicle: o Nose Cone: The nose cone was fabricated of fiberglass. o Airframe: Our airframe was composed of a Kraft Phenolic, with a 6 in diameter. o Fins: We had 4 fins on our rocket. They were made of ¼ in. oak plywood. The innate strength of the material will ensure that the fins will not break upon landing. o Cupplers: Our cupplers are made of cardboard. o Bulk Head and Centering Rings: The internal bulkheads and centering-rings will be constructed out of 0.5 in. solid pine. The pine plywood has a very clean smooth face and very few knots. The use of higher

8 8 grade wood ensures the bulkheads and fins will have uniform wood grain and will be structurally strong in order withstand the stress of flight. Recovery System: Our recovery system consists of the drogue parachute, main parachute, altimeter bay, and ejection charges. Below: the entire recovery system, after landing at our final launch. o Altimeter Bay: Our altimeter bay is roughly 11 in. in length. It is made of cardboard, 2 in. of Kraft phenolic, and pine wood. Other parts include 2 StratoLogger Altimeters, 2 9V Duracell batteries, 6 washers, 4 wing nuts, zip ties, 2 U shaped bolts, 4 nuts, 2 switches, wires, PVC pipe, and clay. Right: Fully assembled altimeter bay, after final launch. o Main Parachute: Our main is 96 in. round parachute. The colors are red and white. It is constructed from nylon material. There is a 1 in. thick shock cord and deployment bag attached to the main parachute. The bag is used to protect the main from the blast of the ejection charges. The shock cord is wrapped with masking tape to absorb energy and to neatly pack the rocket. o Drogue Parachute: The drogue is a 54 in cross parachute. The color is green. It is also made of nylon material. The parachute was able to sustain speed of 45 mph. There are two, a 1 in. thick, shock cords and deployment bag attached to the drogue parachute. The additional length was to ensure that none of the pieces would hit each other or interfere with the payloads, upon decent. The bag is used to protect the drogue from the blast of the ejection charges. The two shock cord are connected with a D- link, and then wrapped with masking tape to absorb energy and to

9 9 neatly pack the rocket. Below: This picture was taken during the testing of the drogue chute to ensure that none of the seams would rip. o Ejection charges: For our final launch, in UT, we had a primary charge of 4.25 grams of 3F black powder, for both the main and drogue. From previous testing we knew this would be enough to separate the sections. As recommended during the LRR, we changed our back up charges, for both the main and drogue, to 4 grams of 4F black powder, since our cups that stored the black powder would not be able to hold 5 grams of 3F black powder. Data Analysis & Results of Vehicle Landing The fin can was damaged on the landing of the rocket. We suspect this is due to a number of factors. First, we used a heavier motor than in our previous flight. Second, the sloshing payload added about an extra 3 lbs. to the rocket. Lastly, the surface of the salts flats is very hard, comparable to

10 10 concrete. We believe that with the additional weight the rocket descended faster, and landing on a harder surface cause the rocket to receive some minor damage on the tips of two fins. Right: Picture of fin during recovery. The tip is bent and some of the wood is split. The Other fin, with the pattern on the left, has some paint chipped on the tip, exposing the wood. It was observed that after landing the fin can bounced and rolled which is what we believe caused the damage on top part of the airframe of the fin can. Right: Picture taken on recovery of rocket. All damage on the rocket is minor, and can be repaired easily. Rocket Launch Success Criteria A successful rocket launch will consist of reaching an altitude at apogee within ± 3.00%. From our RockSim 9simulations, with an Aerotech L850 motor, we had a theoretical altitude of 6270 ft. Our actual altitude was 5419 ft. That is a difference in altitude of 851 ft., and percentage error of 15.7 %. As mentioned before, one of the main contributing factors is that this rocket had an additional 3 lbs. from the sloshing payload. This extra weight would bring d our expected altitude. Payload Summary o Fairing System We ran out of time and did not finish the fairing system. It was described in the PDR, CDR, and FRR as a breakaway airframe that was held by hinges. It was a complicated system in which it would open and allow the hazard detection camera to view the land surface. In hind sight we should have had a backup plan for allowing the HDC to operate independently of the fairing system. It short sightedness on our part to not use a proven acrylic tube as we had done in previous years. o Hazard Detection Camera

11 11 The hazard detection camera was not fl due to the fairing system not being completed. We did not have time to design the airframe for an acrylic section in which the camera could have been placed. We had all the materials for this since we had done it on two previous rockets. We used the Arduino Mega and Uno boards and were able to dload images from the LinkSprite camera and use the wireless capabilities of the Xbee. We had written software for the contours found in the hexadecimal data from the camera but ran out of time to test it. Some of this was described in the FRR. o Liquid Sloshing Payload The purpose of the payload is to obtain a visual of flow patterns developed on liquid (water) contained in two separate tanks of different geometries, a cylindrical and a rectangular tank. Each of the tanks has two compartments, one contains a baffle while the other does not, and compartments are equally filled. The section without a baffle will serve as a control experiment. Above Left, Figure 1: Rectangular (right and cylindrical tank (left). Both containers divided in half. Rectangular tank no baffle in bottom. Cylindrical tank baffle is in the bottom. Water levels in tanks. Also, shows the GoPro pedestal. Above Right, Figure 2: Two tanks on side showing most likely orientation at apogee.

12 12 The flow patterns or waves can provide insight into the nature of forces acting on a rocket as a result of a sloshing payload (for example liquid fuel in a tank), the effect of baffle on the sloshing liquid can be analyzed as well. This experiment can also help us track the rocket s trajectory by analyzing the movement of the fluids held by each tank. Note that for this experiment, we have intuitively filled the tanks with an amount of liquid not sufficient to affect the rocket s travel path, with each tank filled with liquid such that both tanks have equal weights. Tanks are placed on a centering ring; each centered on vertices of an equilateral triangle and a third control load whose weight is a little less than the weight of than a tank is centered on the third vertices. A GoPro Hero 3 camera is placed directly over this load at a height of 3.75 in. The camera accounts for the rest of the weight such that the weight of both camera and control load equal the weight one tank, thus balancing the payload weight distribution. Each compartment of the rectangular tank contained 6 cubic inches of colored water while the cylindrical compartments each originally contained π cubic inch of same colored water. The fluids have been colored with environmentally friendly food dyes to aid visuals, and we assume dyes do not form sediments that can significantly affect the liquid s flow pattern. Data Analysis & Results of Payload Liquid Sloshing Payload The anticipation was that there would be high degree of slosh movements, but that isn t the case in the results obtained. Although, meaningful result could not be obtained from the cylinder tank due to failure of materials and bonds resulting in almost total draining of slosh liquid, the square tank held fluid fairly well and leakage was minimal. The video image obtained from the square tank show the fluid, in the control experiment compartment which had no baffle, move up to the roof inclined toward the direction of rocket travel as the rocket s velocity peaked but, with almost regular wave patterns forming on the free surface which is now upside d. A complete imagery of the baffled compartment could not be obtained for the position of the camera. At apogee the ejection charge fired and there is a violent collapse of the liquid from the roof

13 13 resulting in high degree of sloshing is observed, resulting in severe turbulence within the liquid. Obviously, drogue chute had deployed just after apogee, giving a possible observe free fall or microgravity for approximately 1 to 1.5 seconds. The results obtained can be used to estimate liquid behavior in microgravity. Figure 1 shows tanks after the launch indicating fluid loss in the upper baffle chamber when comparing Figure 1 and Figure 3 (Below). Scientific Value Liquid Sloshing Payload The forces due to waves on the liquid free surface can be studied with regards to how these dynamics affect the rocket s stability. 3-D image to be extracted from the video image, with the wave heights across the free surface plotted against travel velocity of rocket. The results obtained can be projected to altitudes and velocities for which experimental data are not be easily obtainable. Visual Data Observed Liquid Sloshing Payload The video shows several frames in microgravity and warrants further investigation. Some observaitons: 1) The rectangular shaped tank developed elongated fluid extensions. This was the control tank so it had no baffle. It is difficult to determine whether it is the shape of the edges or the baffle. From watching NASA videos of the capillary effect in microgravity it could be the nature of the edges of the tank where the corners meet which draws the liquid. If this is the case it could offer a significant advantage in a weightless environment to draw fluid in by using edge effect which the liquid adheres. If the fuel tank was designed in a star shape we believe the liquid would follow the edges and based on the direction of flow needed one would place a inclined tube with a pump and the fluid would flow into it.

14 14 Above Left, Figure 3: Tanks in rocket before launch. Above Right, Figure 4: Tank after motor burn out, meaning negative acceleration. 2) The cylindrical shape tank showed no perferred position/orientation to the liquid. The tank that held water had a baffle and it s chamber was filled so looking at a surface layer was difficult. In conparision the cylindrical tan showed little movement of the liquid and could be because of the curved surface or the baffle. It is hard to determine and needs firther exploration and direct visual inspection. Payload Conclusions We believe we have a new design for fuel tanks base on the fluid flow seen in our experiment and other data. The design of the fuel tank is a star shape or multi-angled surface oriented lengthwise along the tank. The fuel in microgravity will collect in the star pattern based on the capillary effect of fluids. The fuel will collect in the wedges of the star and when needed one only has to apply another angled surface to the end that the fuel is desired to flow. A slight vacuum from a fuel pump is all that is need and the fuel will flow based on surface tension.

15 15 Figure 7: Face on view of UND s fuel tank design. We propose an interior star pattern that has edges in which liquid will naturally collect in a microgravity environment. Blue is liquid fuel. Figure 8: Edge view of fuel tank. One end would need to be tapered to a point to ensure fluid can connect to all-star channels. Pumps can be aligned at each channel with an inclined surface and draw the liquid off with a slight suction. Only 3 pumps are sh. Lessons Learned Drogue parachute Our drogue parachute had extra material that was pocket-like on the parachute corners. We learned while testing the parachute, which if the extra material is not cut off the parachute will begin to rotate. This rotation caused the lines to become extremely twisted, and could potentially cause the chute to close up. Thus, once we removed the excess material, the parachute performed as expected during testing. Ejection charges From the beginning of the project, we were having issues of the using balloons to contain the black powder. So we switched to small cups. This allowed the charges to perform more accordingly. From the change in the ejection charges during the LRR, we learned that relationship between 3F and 4F black powder is a bit more complicated. The 4 grams of 4F black powder was too large for our rocket, as the data from the altimeters showed. Further testing will need to be done to understand a better relationship when using the different powders for next year.

16 16 Altitude Overall, the rocket maintained a stable flight course, although drags were more significant than anticipated causing the rocket to not attain proposed height. Liquid Sloshing Payload The data obtained is tenuous to interpretation because there had been some liquid leaking in different chambers unequally, so comparisons are difficult make in relation to the control chambers. More time was needed to planning and fabricating several devices with different materials in order to produce a reliable design. Cracks had developed in the cylindrical tank of the slosh payload probably due to stress build up during grinding operations or storage causing significant leaks that team was unable control. Good binding of parts for both tanks had not been achieved, and led to leaks as well. The fluid alignment during rocket s flights brings a new perspective to choosing baffle types and installation procedure. Management The importance in management was the overall theme in this year s project. From the beginning of the project there were communication issues, disorganization, and lack of delegation. These problems lead to some team members being overwhelmed with tasks, especially to meet deadlines, while other felt not included. Eventually, this impacted the retention of team members, which ultimately lead to a shift in leadership towards the end of the project. Looking to next year, we understand how poor management can drastically affect the success of a team, and will make sure to take the necessary action to prevent us from going through all the stress again. Summary of Experience The exercised launch exposes our team to many situations that we would not otherwise experience. This experience was very unique for both new and returning team members because of the change in payload criteria and having the final launch site in UT. Because the experience was very exciting and memorable, most of the team members will be participating next year. We would like to thank everyone for providing us with such an awesome opportunity. Educational Engagement Summary Reached a total of 80 participants.

17 17 Colloquium with the Department of Physics & Astrophysics Date: Monday, February 10 at 8:00 PM Participants: 80 Topic: "SLS: The Future of Modern Rocketry" Engagement: Following the talk, attendees will be given the opportunity to observe the night sky through a telescope. Budget Summary EXPENSES QUANTITY PRICE PER UNIT COST FUNDED EXPENSES OUTSTANDING Travel / Gas Airlines (mileage and gas) 3 $ $ yes - Space Grant Sub Cost $ Lodging May 14, 2014 Salt Lake City, UT May 15, Salt Lake City, UT May 16, Salt Lake City, UT May 17, Salt Lake City, UT 1 $ $ $ $ $ $ $ $ yes - Space Grant yes - Space Grant yes - Space Grant yes - Space Grant Sub Cost $1, Rocket Supplies Air Frame ( in) 2 $ $ $ Centering Ring 3 $7.00 $21.00 $21.00 Motor Mount Tube 1 $14.00 $14.00 $14.00 Nose Cone 1 $49.45 $49.45 $49.45 Stiffy Tube 2 $9.95 $19.90 $19.90 Tube Coupler 2 $8.25 $16.50 $16.50 Parachute 96" 1 $89.95 $89.95 $89.95

18 18 Drogue 54" fabric and paracord 1000 Series Rail Beads Shockcord (per yard) 1 $20.95 $20.95 $ $2.65 $5.30 $ $1.10 $6.60 $6.60 Casing 1 $450 $ Motor Aerotech L850 4 $ $ $ Rocket Kit 1 $40.00 $40.00 scrapped from previous rocket PerfectFlite 2 $99.95 $ Sub Cost $2, $1, Misc. Supplies 1/2" by 6' Plywood 1 $15.00 $15.00 $ /4 6 Plywood 1 $15.00 $15.00 $15.00 Nuts 20 $0.25 $5.00 $5.00 Washers 20 $0.25 $5.00 $5.00 Eye Bolts 4 $1.50 $6.00 $6.00 Xacto Knife 1 $1.97 $1.97 $1.97 Batteries 6 $5.00 $30.00 $30.00 Paint & gloss 6 $10.00 $60.00 $60.00 Paper towels 1 $3.99 $3.99 $3.99 Plastic cups 1 $5.99 $5.99 $5.99 Sub Total $ $ Payload Supplies Arduino Mega $58.95 $ Mego Protoshield for Arduino D2523T Helical GPS Reciever Copernicus II DIP Module Xbee Pro 900 Wire antenna Xbee Pro 900 U.FL Connection 2 $14.95 $ $79.95 $ $74.95 $ $42.95 $ $42.95 $ $ $29.90 $ $ $ $171.80

19 19 LinkSprite JPEG Color Camera TTL Interface 2 $49.95 $99.90 Open Log 2 $24.95 $49.90 TEMT6000 Breakout Board 2 $4.95 $9.90 Mini Photocell 2 $1.50 $3.00 Light to Frequency Converter - TSL235R Polymer Lithium Ion Battery - 6Ah CamOne Infinity w/ gps module 2 in. plexiglass glass tube 48" long 2 $2.95 $ $39.95 $ $ $ $99.90 $49.90 $9.90 $3.00 $5.90 $39.95 $ $50.00 $50.00 $50.00 Sheet of plexiglass 1 $30.00 $30.00 $30.00 Hinges 4 $5.00 $20.00 $20.00 CamOne GPS Module 2 $50.00 $ $ Sub Total $1, $ Other Expenses T-shirts 4 $15.00 $60 $60.00 Sub Total $60 $60.00 Total $ Funding ATK $ Funding ATK MSP $ Total Cost $8, $0