Momentum 360LM PDOF Lite


Overview: Computes the Impact Speed, DeltaV and PDOF data for angular collisions.


Entry into Module:


This module of the program is normally entered by clicking on the REC-TEC block in the upper left of the REC-TEC Window causing the drop-down menu to appear. Place the cursor on the Momentum block and click on 360LM PDOF Lite (V1 and/or V2) on the sub-menu to initiate this module.


Under certain circumstances, the user may choose to use the Files block instead of the drop-down menu approach. Selecting any file with a .PFL extension in the Dialog box accessed from either the Open Single File or Open Multiple Files block opens this module.


Selecting AutoLoad [ON] from either the Setup Menu or the AutoLoad Icon on the upper right side (third line) of the REC-TEC Window automatically loads the scenario that was on the screen when the module was closed, either individually, or when the program was closed. With AutoLoad [OFF] on the main REC-TEC Window, modules will start without loading a file.


Data Entry:


This module contains four data entry blocks for each of the two Vehicles:

             Approach Angle (Number)

             Departure Angle (Number)



             Weight (Number) 360LM


             Departure/Post-Impact Speed (Number) - Entering X for the Speed of V3 initiates entries and computations using the Longitudinal DeltaV (CDR) and user supplied PDOF for Vehicle 1 in lieu of the post-impact speeds of both vehicles. This computation can be used as a conformational check on other data.

             Longitudinal DeltaV for Vehicle 1 - (CDR download)

             PDOF (1) - (CDR download)

             Slip Angle - Angle between the Longitudinal Axis of Vehicle 1 and its Pre-Impact direction of travel


Entry of specific (known) data in the data boxes sufficient to generate an answer causes output information to appear in the Output frame. As the input data is changed, the output data is automatically updated without the need to tell the program to update the output.



The output from this module consists of the input data plus:


             Speed 1 Impact Speed Vehicle 1

             Speed 2 Impact Speed Vehicle 2


             Angle (C) Closure Angle

             Angle (S) Separation Angle


             Speed (C) Closure Speed

             Speed (S) Separation Speed


             PDOF A1 Direction of Impulse Vector relative to heading of Vehicle 1

             PDOF A2 Direction of Impulse Vector relative to heading of Vehicle 2


             Delta V1: Change of Velocity Vehicle 1

             Delta V2: Change of Velocity Vehicle 2


             eVelocity: Coefficient of Restored System Velocity (Restitution)

             rVelocity: Coefficient of Retained System Velocity (Vs/Vc)


Diagram shows vectors for both vehicles with the Approach Momentum Vectors parallel. The Post-Impact Momentum Vectors are connected to the Approach Momentum Vectors by the PDOF/DeltaV Vectors.




Several Command Buttons appear in a frame located at the lower right corner of the module Window. The Command Buttons allow the user to engage options including the option to Open and Save the data required to generate the scenario shown on the screen at the time the file was saved.


             Open .PFL File Calls up a Dialog box, which Opens any pre-existing .PFL file and displays the output results.


             Save .PFL File Calls up a Dialog box, which Saves data on the screen to files with any user-selectable filenames. This is independent of the automatic saving as LastFile.PFL of the data at the close of this module or the close of the program.


             Formulae Opens a word processor (set by the user in Setup) with a file showing the basic formulae used in this module of the program. While the user may add to or modify the information in this file, it does not change the formulae imbedded into the program.


             N This button toggles a graphical number pad on the screen that can be used to enter data into the input boxes without using your keyboard number pad. This may be useful for presentations as data entry can be accomplished using a wired/wireless mouse.