VacTran 3 Manual, страница 7

The model can then be used in system models to see theeffect on pump down time or rate of rise.Raw data conductance:Used when measured data is available for conductance of a piping element, insteadof using one of the built-in parametric models (such as an elbow)Series conductance ModelUseful to simulate a group of conductance elements in series when they are usedin many placesParallel conductance modelCombines parallel conductances into a single element that can be combined inseries with other elements.Pump StationSystem models use multiple pump stations for different pressure stages of pumpdownGas Model:Gas models are used in system models and affect conductance calculationsLibrariesUse libraries when published data (permeation, out gas, piping, o-ring sizes) is available that can be used inVacTran’s parametric equations.StudiesSimple system study:leftUse a Simple System study when a quick estimate of pump down time or pumpsize is needed. The accuracy of this estimating tool will vary depending on theattributes of the real system being modeled.Parallel / series study:leftParallel and series studies are used to optimize the pipe diameter so that aneconomic design is achieved that is not conductance limited.© 2011 Professional Engineering ComputationsIntroduction3.529Where are the models’ dependencies?Some model types are actually reusable components of larger models.

For example, several system models canuse the same pump model for a particular turbo pump. Model the pump once, and link the system to it. A pumpstation can be built from pump models and conductance models, but raw data gas loads and gas models are notapplicable. The table below highlights component models and larger models in which they can be used.Component modelsWhere usedSeries orparallelconductancePumpRaw datagas loadRaw dataconductanceGas modelSystem modelUsedUsedUsedUsedUsedPump StationUsedUsedNot UsedUsedNot UsedSimplesystem studyNot UsedNot UsedNot UsedNot UsedUsedParallelconductancestudyNot UsedUsedNot UsedNot UsedUsedSeriesconductancestudyNot UsedUsedNot UsedNot UsedUsedThe illustration below shows the dependency of a pump station on pump and conductance models.© 2011 Professional Engineering Computations303.6VacTran 3Some models can generate othersIt can be very helpful to create a new model from an old one, and examples of this will be shown throughout thismanual.Generated modelsPump StationSystem modelRaw data conductanceParent modelPumpSystem modelYesYesNoNoYesNoParallel conductance studyYesYesNoYesSeries conductance studyYesYesNoYesSimple system studyNoYes© 2011 Professional Engineering ComputationsIntroduction3.7New features in version 3If you have used previous versions of VacTran, the following list of new features will be of interest to you.1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.17.18.19.Floating tool barsParallel conductance modelsSeries conductance modelsPump Station modelsPump DigitizerVolume / area calculatorRate of Rise calculationEmbedded floating calculator6 station pump modelsAdvanced station settings dialogAdvanced pressure settings dialogEmbedded screen captureAnnulus conductanceEllipse conductanceTriangle conductanceRectangle conductanceCone conductanceSlit conductanceGraph galleryNew graphing functions:20.

Gallery settings21. Advanced legend options22. Preset styles23. Bitmap backgrounds24. Data cursor25. Advanced grid styles26. Gradient backgrounds27. Export to WMF, BMP, PNG, JPG© 2011 Professional Engineering Computations31324VacTran 3First lookIf you ran the setup program and installed the hardware key as described in the previous section, you're now readyto run VacTran.1) From the Start menu on your Windows desktop, select VacTran under ProgramsOr2) Open the VacTran folder that you created when you installed the program.

Doubleclick on the VacTran application icon.VacTran start up screenSee also:The VacTran startup screenVacTran Help SystemThe tool barMain menuSpecial tools© 2011 Professional Engineering ComputationsFirst look4.133The VacTran startup screenThe VacTran startup screen contains a menu bar, a tool bar, two permanent windows for displaying text and graphs,and two floating palettes for inserting conductance and gas load elements into models.© 2011 Professional Engineering Computations34VacTran 3The Main Graph Window and the Main Text Window are permanently visible.

These are used in almost all partsof VacTran for displaying calculated information. Each time a curve is generated, it will be displayed in the MainGraph Window. The corresponding data, which went into the graph, will be simultaneously shown in the Main TextWindow as shown below. The text updating can be shut off, if desired, to speed up calculations. All calculationsthat update either the Graph or Text Window will clear the previous contents, but text and graphs can be saved first.© 2011 Professional Engineering ComputationsFirst look4.235VacTran Help SystemVacTran includes a full-function online reference featuring hypertext linking, text search capability, and contextsensitive topics relating to the origin of the help call.

Most dialogs in the program have a Help button, or you canstart help from the main menu. If you select thebutton from the tool bar, the following contents page will be displayed. Click on any underlined topic todisplay it.© 2011 Professional Engineering Computations364.3VacTran 3The tool bar(click to expand)Many of the common VacTran functions are included on the tool bar, located just under the main menu bar. Someof these buttons may look familiar to you from other Windows applications. A representative sample is shownbelow. A hint pops up for each button when the mouse is hovered over it.Activates Open Document dialog, lets you open an existing fileActivates Save dialogActivate New Document dialog, lets you create a new modelOpens or creates notes associated with a modelAdds a new element to the current model, such as a conductanceDeletes the highlighted element from the current modelSelect a new gas modelActivates the Graph Controls dialogActivates the Units of Measure dialogActivates the Environment dialogStart a Parallel conductance studyStart a Series conductance studyBring the Conductance palette to the front of other windowsBring the Gas load palette to the front of other windows+Activate VacTran Help© 2011 Professional Engineering ComputationsFirst look4.437Main menuThe Main menu is always visible within VacTran.

It contains the following drop down menus.File menuThe File menu contains common file management commands, which are used in the same manner as mostWindows programs. In addition, most recently opened files are listed. Open recent files… displays a list of recentfiles that have been opened.Select New to create a new model as shown:© 2011 Professional Engineering Computations38VacTran 3Edit MenuThe Edit menu contains common clipboard commands for text and graphics: Cut, Copy, and Paste, while SelectAll and Clear All commands apply to text windows or text entry fields only.Model menuThe Model menu contains several groups of model editing functions:© 2011 Professional Engineering ComputationsFirst look39Clicking on any one of the Environment settings will activate the Environment dialog, as shown below.Add, Replace, and Delete are used to edit models of various types.Get info is used to examine data entries, Graph now forces a graphing function, Write report dumps model datato the text window.Gas model changes the current system gas, Current gas info shows information on the current gas.© 2011 Professional Engineering Computations40VacTran 3Defaults menuThe Defaults menu sets the default conditions of graphs, units of measure, and automatic updates.

All defaultsettings on this menu are saved at the end of your VacTran session.© 2011 Professional Engineering ComputationsFirst lookAn example of a Defaults setting is the Units of Measure dialog shown below:© 2011 Professional Engineering Computations4142VacTran 3Graphs menuThe Graphs menu contains most of the graphing options in VacTran for System models, Pump models, Raw datagas load models, Raw data conductance models, Simple systems and Conductance Studies.

Graph commandswill be active when a displayed model has enough data in it.Each type of graph has a unique axis setting, which can be changed at any time using Graph Controls under theDefaults menu.Any graph can be copied and pasted to a file, clipboard, or another graph window on the screen.

Complete scalingand orientation options are available by selecting the Export button on the Main Graph Window.© 2011 Professional Engineering ComputationsFirst lookAn example of a pump down graph is shown below:© 2011 Professional Engineering Computations4344VacTran 3Tools menuThe Tools menu activates one of the conductance studies, the Simple System Study, or one of several other toolsas shown in Special tools.Window menuThe Window menu provides Cascade, Tile, Arrange Icons, and Minimize All commands to arrange VacTranwindows and icons on the screen.Access to any open VacTran window is provided using the numbered menu commands.© 2011 Professional Engineering ComputationsFirst look45Help menuThe Help menu gives you ready access to on-line help contents and status information on the hardware key.About VacTran activates the window shown, which contains links to the VacTran web home page and a link toemail for customer support.© 2011 Professional Engineering Computations464.5VacTran 3Special toolsSimple system studyThis tool provides quick estimates for getting started before doing more detailed modeling using a system model.Each tabbed page solves for a different variable, such as pipe length for a given set of pump down constraints.