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Baseball Panels

If you click the "Play Ball" button at the bottom of the screen, the view panel will show a schematic drawing of the baseball flow problem.

The Baseball View Panel displays the ball and the streamlines of flow around it as viewed from above, looking down. Home plate to the left and the pitcher's mound to the right. The flow appears to move from left to right as the ball moves through the air. The green streamlines would move around the right side of the ball as viewed by the pitcher while the yellow streamlines move to the left. At the bottom of the panel are two buttons to set the pitcher to either a Right Hander or a Left Hander. The Up/Down, Left/Right, and Out/In sliders let you change the position and size of the baseball view.

The Baseball Input Panel below the View Window is used to control the conditions of the pitch. You can select the altitude of the location; this affects the air density and the amount of force that can be generated on a curve ball. Several locations are given as selection buttons below the altitude input. The user can vary the speed of the pitch and the spin put on the ball by using the input boxes and sliders. To move the slider, place the cursor along the slider and click the left mouse button. The value of the slider is shown in the input box. To more accurately specify the input value, type the value into the input box. Simply click in the input box, delete the original value, type in the new value, and press the "Enter" or "Tab" key when finished. The button on the slider will move corresponding to the input box value. For the spin input, just click on the red words (Curveball, Fastball, Screwball) located below the slider and the appropriate spin will be set on the slider.

As the speed is increased, the flowing streamlines in the view window will appear to speed up. As spin is put on the ball, the view window will show the ball's rotation and the (slight) deflection of the streamlines. Spinning the ball creates a side force ("Magnus" effect) which causes the ball to curve in flight. The magnitude of the side force is shown in the output box and horizontal gauge at the bottom of the input panel. The direction is color-coded to correspond with the view window.

The Plotter View Panel displays the pressure or speed variation around the ball. Once again, the color of the line corresponds to the surfaces shown in the Baseball View Panel. Notice that the lines separate when a spin is put on the ball. You can look for these speed differences using the airspeed probe with the Probe Control Panel.

For the baseball problem a special plotter option has been included. Pushing the "Ballpark" button on the Plotter Input Panel will change the plotter display to the view of a baseball infield. Using this display, you can see the trajectory of a thrown pitch for the conditions given in the input panel. Putting spin on the ball causes the trajectory to curve in the Plotter Window. The trajectory is displayed as a series of dots which show the ball's position at each 0.05 seconds. The slower the pitch, the greater the number of dots which appear. Adding up the number of dots and multiplying by .05 seconds will give the time it takes to reach the plate. You may vary the Release Point of the pitch and the Release Angle of the pitch by using the sliders in the Plotter Input Panel.

You can explore the flowfield around the ball by using the Probe Control Panel located in the Plotter Input Panel.

Ready to play! Go to the Baseball Lessons.