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Modelling longitudinal waves in a long train-set

• Introduction
• Download the example
• Run the runf/long_train_Ccoupl.tsimf
• Examine the results in GPLOT

Introduction

The train-set consists of one locomotive m_loco pulling 36 wagons m_wagon_tare carrying load m_load. The train-set enters an upwards slope which causes a retardation of the locomotive which compresses the train-set. On top of the upward slope max power on the locomotive is applied which pulls all wagons apart again. When the acceleration wave reaches the last wagon of the train-set, the longitudinal acceleration has grown into a level which causes sliding of its load.

Download the example

• Download the tar-file long_train.tgz
• List the contents of the tar-file with "tar tvfkz long_train.tgz"
• Extract the contents of the tar-file with "tar xvfkz long_train.tgz"

Run the example runf/long_train_Ccoupl.tsimf

• Double-click file runf/long_train_Ccoupl.tsimf and select open->run with the right mouse button.
• As output the following files will be produced:

  id/long_train_Ccoupl.id	MPdat-file for plotting in MPLOT
  gp/long_train_Ccoupl.gp	GPdat-file for animation in GPLOT

Examine the results in postprocessor GPLOT

• Double-click directory runf/ in the subdirectory text area.
• Double-click file runf/long_train_Ccoupl.tsimf in the file text area.
• Press the Gplot-pushbutton.
• Open file gp/long_train_Ccoupl.gp by selecting File->read_GPdat in the pulldown menu bar
• Select View->view_side from the pulldown menu bar
• Click View->show_1_diag and set "Deformation scale fact" to 25 approximately.
• Zoom out by pressing the left mouse button and drag the mouse downwards, or use the roller on your mouse.
• Start the animation by pressing the Fwd–pushbutton.
• The observer moves at constant speed Vo. If the speed of the observer does not agree with the speed of the train-set the model can be moved longitudinally by pressing the right mouse button and drag the mouse to the left or to the right.
• Observe the last wagon and its load when the acceleration wave reaches the end of the train-set