Sound Wave Simulator allows you to explore the Doppler effect and the formation of Mach waves. A "bug" generates a series of sound waves which are transmitted at the speed of sound. You can vary the speed of the bug from zero to twice the speed of sound (Mach 2) by using a slider. The change of wavelength associated with the Doppler effect at lower speeds is illustrated. The formation of Mach waves which are inclined to the direction of motion at a unique Mach angle are also illustrated.

RocketModeler II was developed at the NASA Glenn Research Center in an effort to foster hands-on, inquiry-based learning in science and math. RocketModeler is a simulator that models the design and flight of a model rocket. The program works in two modes: Design Mode or Flight Mode. In the Design Mode, you can change design variables including the size of the rocket body, the fins, and the nose cone. You can also select different materials for each component. You can select from a variety of standard solid rocket engines. The program computes the center of gravity and pressure for your rocket and determines the stability. When you have a design that you like, you can switch to the Flight Mode, where you can launch your rocket and observe its flight trajectory. You can pause at any time to record data and then continue the flight through parachute deploy and recovery. This program has recently (Oct 8, 2004) been upgraded to support stomp rockets, bottle rockets, and ballistic shells in addition to solid model rockets. It also supports both English and metric units.

KiteModeler was developed in an effort to foster hands-on, inquiry-based learning in science and math. KiteModeler is a simulator that models the design, trimming, and flight of a kite. The program works in three modes: Design Mode, Trim Mode, or Flight Mode. In the Design Mode, you pick from five basic types of kite designs. You can then change design variables including the length and width of various sections of the kite. You can also select different materials for each component. When you have a design that you like, you switch to the Trim Mode where you set the length of the bridle string and tail and the location of the knot attaching the bridle to the control line. Based on your inputs, the program computes the center of gravity and pressure, the magnitude of the aerodynamic forces and the weight, and determines the stability of your kite. With a stable kite design, you are ready for Flight Mode. In Flight Mode you set the wind speed and the length of control line. The program then computes the sag of the line caused by the weight of the string and the height and distance that your kite would fly. Using all three modes, you can investigate how a kite flies, and the factors that affect its performance.

Isentropic Flow Calculator solves the isentropic flow equations for a variety of inputs. Variables include the Mach number, static to total pressure, temperature, and density ratios, dynamic to static pressure ratio, critical area ratio, corrected airflow per unit area, Mach angle, and Prandtl-Meyer angle. Specifying any one variable determines the value of all the other variables.

Interactive Nozzle Simulator solves the isentropic flow equations for the flow through a rocket nozzle, a converging- diverging turbine nozzle or a converging turbine nozzle. Input variables include the throat area, throat to exit area ratio, total pressure and temperature in the plenum, and free stream pressure. You can select from a variety of propellant combinations, or specify your own molecular weight, ratio of specific heats, and combustion temperature. Output include the flow through the nozzle, the thrust, specific impulse, exit velocity and Mach number, and exit static pressure.

Multiple Shock Wave Simulator solves the flow equations for supersonic flow past multiple wedges. Input variables include the Mach number, wedge angles, and the spacing between the wedges. Wedges may be located in series or opposite each other. Depending on the combination, attached oblique shocks or a detached normal shock is generated. The simulator computes the static and total pressure ratio, the temperature and density ratio, the shock angle, flow turning, and the downstream Mach number. A graphic shows the multiple shock intersections and reflections. This program also solves the single wedge problem; generating an oblique or normal shock, or a centered expansion fan.

Atmosphere Applet: This program lets you study how the properties of the atmosphere change with altitude. You can study the atmosphere of either the Earth or Mars. The equations used in this program are taken from the ICAO standard day model for the Earth and from some curve fits of the Martian atmosphere gathered by the Global Surveyor spacecraft. Using the airplane graphic you can select an altitude, or you can type an altitude into the input box. The program instantly outputs a selected property and displays the local temperature and pressure on gages. You can output the temperature, pressure, density, local speed of sound, Mach number for specified velocity, or the ratio of aircraft lift to the lift on Earth at sea level. Input and output can be given in either English or metric units.

The GasLab: This is a series of computer animations which demonstrate all the possible combinations of the ideal gas law or equation of state. Gases have various properties which we can observe with our senses, including the gas pressure, temperature, mass, and the volume which contains the gas. Careful, scientific observation has determined that these variables are related to one another and the values of these properties determine the state of the gas. In a scientific manner, we can fix any two of the four primary properties and study the nature of the relationship between the other two by varying one and observing the variation of the other. The variations are demonstrated using computer graphics in the animated gas lab.