Free software makes learning fun!

The NASA Glenn Research Center has developed a series of interactive computer programs that are aimed at educating students in the fields of mathematics, physics and aerospace.

All of the programs are Java applets which run in a browser, on-line, over the World Wide Web. They can also be downloaded to your computer so that you can use them without being on-line.

FoilSim II computes the theoretical lift of a variety of airfoil shapes. The user can control the shape, size, and inclination of the airfoil and the atmospheric conditions in which the airfoil is flying. The program includes a stall model for the airfoil, a model of the Martian atmosphere, and the ability to specify a variety of fluids for lift comparisons. The program has graphical and numerical output, including an interactive probe which you can use to investigate the details of flow around an airfoil.

Using the CurveBall applet, students learn more about aerodynamics by controlling the conditions of a big league baseball pitch. You can vary the speed of the pitch, the spin on the ball, the release point, and the location of the stadium which affects the atmospheric conditions and the amount of curve on the ball. The program will compute balls and strikes and tells you how far your pitch passes the centre of the plate.

For its part, EngineSim is a simulator that models the design and testing of jet engines. The program works in two modes: Design Mode or Tunnel Test Mode. In the Design Mode, you can change design variables including the flight conditions, the engine size, the inlet performance, the turbo machinery compressor and turbine performance, the combustors or burner performance, or the nozzle performance. For a turbofan engine design you can also vary the fan performance and the bypass ratio. When you have a design that you like, you can switch to the Tunnel Test Mode which simulates the testing of a jet engine on a test stand. You can then vary the test altitude, flight speed and throttle setting. Several existing engines are also modelled in EngineSim.

Next up, there is the Rangegame program that presents a variety of multiple choice maths and physics problems involving aircraft performance. Students can choose from several different types of aircraft and must answer questions about the range, fuel usage, acceleration, velocity and location of the aircraft during take-off. RangeGames can record your answers for teacher evaluation, or you can just play for fun!

For its part, the RocketModeler program lets you design and study the flight of a model rocket. You can vary the size of the rocket, the number of fins, and the materials used to construct the rocket. You can choose from a variety of available model rocket engines and test fly your rocket on the computer. The program computes the stability of your design and the flight trajectory. Output includes the maximum altitude which the rocket achieves. You can then compare the computed and actual performance of your model rocket.

But if you would rather fly a kite, then why not try KiteModeler. You can select from five different types of kites and then vary the length, width and types of materials used to construct the kite. You then trim the kite by setting the length of the bridle and tail and the position of the knot attaching the control line to the bridle. Finally, you test fly your kite on the computer by setting the wind speed and the length of control line. The program computes the aerodynamic forces, weight, and stability of your design and the shape of the control line as it sags under its own weight. Output includes the maximum altitude which the kite achieves. You can then compare the computed and actual performance of your kite design.

The Atmosphere Applet, on the other hand, lets you study how pressure, temperature, and density change through the atmosphere. You can study the atmosphere of the Earth or of Mars. Since speed of sound depends on the atmospheric gas and the temperature, you can also output the local speed of sound and the Mach number for a selected aircraft velocity. You can either input a selected altitude, or change altitude using an aircraft slider.

While the GasLab Program is a group of computer animations which were designed to help high school chemistry students learn about the basics of the gas laws and the equation of state. The state of a gas is determined by the pressure, temperature, mass, and volume of the gas. The program lets you fix two of these variables and observe the relation of the other two variables by changing the value of one of them.

The last group of Undergraduate Programs aim to help engineering students learn about the basics of high speed aerodynamics and engine operation. The programs solve for the flows across shock waves and expansion fans, the flow through crossed and reflected shocks, and the properties in regions of isentropic flow. There is also a special version of EngineSim for undergraduates.