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# AeroSpin - New ride 2016

Liseberg's new family ride 2016, AeroSpin, is a Sky Roller from Gerstlauer.

Aerodynamics in the Amusement Park: interpreting sensor data for acceleration and rotation

The airplanes are raised 35 m from the ground. While you make 11 turns/min around the tower the flight diameter is 21.2m, according to the data sheet. By changing the angle for the left and right wing, the rider can influence the ride, from a sightseeing mode where you are moving around a vertical axis ("yaw"), to a wild ride where the whole airplane rotates around its own axis ("roll").

See also pictures, movies and presentations of  Sky Rollers in other parks.

Watch the movies and consider how the position of the wings can cause the plane to rotate.

Hint: There is no engine causing the plane to roll. Something mus exert a torque around the axis of the plane, and of this torque depends on the position of the wings.

### Acceleration and rotation

If you have a good pocket that can be closed safely, you might be able to take data with your phone, e.g. with the app Physics Toolbox. (Choose "Roller Coaster" for an Android and accelerometer and gyro for an iPhone)-

### Calculations and considerations

Use the information from the data sheet for the exercises below, i.e. 11 turns/min around the tower and a total diameter of 21.2m. (Don't forget to account for the reduction of diameter due to the rider location, about 137 cm from the tip of the wing, for one of the outer planes - see the measurements)

• How far do you travel in one full turn around the tower?
• How fast do you move around the tower?
• How large is the centripetal acceleration due to this motion?
• What happens if the wind speed is higher than the airplane speed?

## Accelerometer graphs

The picture to the right shows coordinates for a rabbit according to standards for ride safety (these differ from the coordinates of the phone)

ThBilden till höger visar koordinataxlar för en kanin enligt standard för åkattraktioner (telefonens koordinater är annorlunda).

In a Sky Roller you move in the positive direction along the x-axis (which moves together with you) and by moving the wings you can also rotate around that axis ("roll").

The main rotation around the tower is around the  "Z axis" which coincides with the  z axis if you sit straight up. (The Z-axis does not change during the ride.) Can you express the  Z-axis in terms of rabbit coordinates during a roll?

The graphs below show accelerometer data in the y direction for two rides. The graph to the left shows a ride which only nearly makes a full turn, while the graph to the right shows data from a ride rolling more than 40 turns.

Read more about the interpretation of the data in our paper: Aerodynamics in the amusement park: interpreting sensor data for acceleration and rotation (with a video summary).