Illinois Junior Academy of Science - Yearbook (Urbana, IL)

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Experimental Determination of the Drag Force Ex- erted on a Model Rocket KEN CON'RA'D Glenbard East High School Lombard K- K . 3, ,gh sf,-5 - . it ff 4 , , 1 ,. i if gk , . , THE 5 HUQTA EET! MQTSSK QF BRAC The altitude, velocity and rate of acceleration of any rocket can be calculated by classical physical laws. Unfor- tunately, however, in practice the achieved results of any projectile in the atmosphere are less than the theoretical re- sults, because of air drag. I have concluded that the actual observation of a rocket in flight is the easiest way to deter- mine the drag force acting on it. To determine this drag force, three tracking systems were devised. The three sys- tems record the rocket's acceleration, maximum altitude, and the period of time it takes to reach the maximum altitude. The rocket's acceleration for any instant is recorded on a revolving cylinder by the movement of a lead weight sus- pended on a spring. From the acceleration, the actual ve- locity of that particular flight can be determined lthe area under an acceleration-time graph is velocityl and in general, the coefficient of drag can be found. If the coefficient of drag, as determined experimentally, is known for any par- ticular shape and finish of rocket, as well as the weight and specific impulse or the thrust and its duration. then the characteristics of its flight can accurately be predicted. In theory, when the drag coefficient is known, all of the actual characteristics of a perfect rocket flight can be computed exactly, such as acceleration rate, velocity, and distance traveled for an instant of the flight. However, vary- ing thrust, mechanical and human error and other factors caused the estimated results to be within 154k of the actual results. Rocketry From The Model Up GEORGE DOLAND 193 Wheeling High School Wheeling Sponsor: Edith Beniamin The purpose of my project was to show and demonstrate the many problems involved in making, designing and launch- ing rockets of all types: also I wanted to show the rockets of the present and future. I tried to get information on rocket problems and advanced rocketry. Then, with this information, I built models. Also, in addition, I designed and built my launching pad and ion rocket and demonstrated lt. Then, finally, I successfully launched a fish and brought it back alive. After this launching, I sent a second fish up twice to find out if the fish was weak from acceleration or the sudden landing. It was mainly, I felt tstill not conclusivel from the sudden landing, as the parachute did not open in the one instance, and though the fish recovered successfully it seemed weak for a longer period of time. UWB all ' 912 'Q CHRIS LUPPENS Sf. Bede Academy Peru f cell uwgig-rnlXBD lun' The flights of the Gemini spacecraft brought to light the potential power of the fuel cell. The idea of the fuel cell specifically includes an electro-chemical device that directly converts the energy of a chemical redox equation into elec- trical energy. The word directly is the key to the success of the fuel cell since the possible electrical efficiency is IOOW. Present operating fuel cells have reached a 99+W efficiency. My project concerned the development of a self-contained fuel cell power unit housed in a satellite. The experiment consisted of 3 phases: Il The actual construction of two operating oxygen- hydrogen fuel cells using nickel mesh as electrodes, platinum for the catalyst, and potassium hydroxide as the electrolyte. 23 The construction and operation of a laboratory gas supply consisting of pressurized gas tanks, whose gas was fed through two glass tubes containing water. The gas was bubbled in this manner to achieve IOOW humidity when it reached the fuel cells. 33 An experimental supply of gas obtained by traditional electrolysis of water. This unit was powered by either a rectifier or a set-up consisting of solar cells charging nickel cadmium batteries. All the above work proved profitable for the final de- sign of the satellite unit. This unit contains electrolysis apparatus, a special water tank, stack fuel cells. control panel, dielectric pumps, special silicon membranes, solar cells, nickel cadmium batteries, and various connections. The unit in theory is self-sustaining in theory, and is capable of op- erating in zero gravity. A satellite housing was designed to contain the power supply. Its approximate weight is 24 pounds, its output 24 volts D.C. at 5 - 10 volts, and its outer diameter around three feet.

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AERONAUTICS

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xii Q 'Lana - Q . ANTHROPOLOGY l J-f -L , i ktnui ff. Mat .. WM X .. , 1-N .L , FNW5' QB.