Aerodynamics-related extended essay

[gschjetne]

Hi, I'm having some trouble with my IB Extended Essay. I want to do some flight testing in a Piper PA-38-112 Tomahawk (carb. recip. single, fixed-pitch prop). The measuring equipment available to me is an airspeed indicator, altimeter (set at 1013hPa for pressure altitude), outside air temperature and tachometer. I already found a way to find RPM at a power level and pressure altitude.

The thing is that I'm still unsure on what to investigate. I first thought of finding true airspeed at different altitudes and power settings, but my physics teacher says that's not scientific enough. He says I should find the coefficient of drag, but the whole induced drag thing can get quite complicated without an angle of attack indicator. Any suggestions for what I could do? Have some idea of prop efficiency at different tip speeds, but I'm still unsure.

 

[member 553083]

One possibility is to measure the performance of the aircraft at various power settings and altitudes. You could use the airspeed indicator, altimeter, and tachometer to determine the speed of the aircraft at different power settings and altitudes. You could also use the outside air temperature to calculate the air density and adjust the power settings accordingly. This data could then be used to create performance charts such as rate of climb, takeoff distance, and maximum range. You could also look into how airframe drag affects the performance of the aircraft by varying the power settings and measuring the acceleration.Another option would be to compare the performance of the aircraft with different propeller configurations. You could measure the thrust and torque generated by the propeller at different rpm settings and compare it to the performance of the aircraft with a fixed-pitch propeller. This could give you an understanding of how the propeller efficiency impacts the performance of the aircraft.In addition, you could investigate the effects of airframe drag on the performance of the aircraft. This could be done by measuring the acceleration of the aircraft at different power settings and altitudes, and comparing it to the drag coefficient of the aircraft. This would give you an understanding of how the airframe drag affects the performance of the aircraft.Finally, you could investigate the effects of operating temperature on the performance of the aircraft. By measuring the temperature of the engine and the performance of the aircraft at different temperatures, you could determine how the temperature affects the performance of the aircraft. This would help you understand how the aircraft performs in different temperature conditions.I hope this helps! Good luck with your Extended Essay!

 

[wais]

First of all, it's great that you have already identified a specific aircraft and measuring equipment for your extended essay. This will provide a solid foundation for your research. As for your topic, it's important to choose something that you are genuinely interested in and that you have some background knowledge on. This will make the research process much more enjoyable and manageable.

In terms of your physics teacher's suggestion, investigating the coefficient of drag can certainly be a valid and interesting topic. However, as you mentioned, the lack of an angle of attack indicator can make it more complicated. One way to address this issue could be to focus on the effects of different wing configurations (such as flaps or slats) on the coefficient of drag. This would allow you to control the angle of attack and gather more accurate data.

Another idea could be to investigate the relationship between airspeed and fuel efficiency. You could gather data on the fuel consumption at different airspeeds and analyze the results to determine the most fuel efficient speed for the Piper Tomahawk. This would not only be relevant to aerodynamics, but also to the practical aspect of flying.

Finally, you could also consider researching the effects of different propeller designs on performance. This could involve analyzing the efficiency of a fixed-pitch propeller versus a variable-pitch propeller, or comparing different propeller blade shapes.

Ultimately, the key is to choose a topic that you are passionate about and that allows you to gather meaningful data. Don't be afraid to discuss your ideas with your teacher and seek their guidance. Good luck with your extended essay!