dymola

问题 Is there a guide for increasing the ability of convergence during the initialization of the nonlinear system in Dymola? Usually, the connector contains start values, but they are not always suited for the model I build, so there might be a divergence issue during the initialization. How could I avoid this issue? 回答1: The Dymola User Manual Volume 1 has several chapters, which deal with the initialization of nonlinear systems. In Dymola 2020 the chapters are: 5.6.8 Initial guesses for

问题 Is it possible to use the previous value of the time varying variable for eg: Suppose I have pipe whose inlet temperature is 298K with a specified uniform mass flow(m_flow), now suppose i am heating the pipe using a heater of 100 watts. The outlet temperature will be attain a higher temperature of suppose 302K, now if i have to use this outlet temperature as my inlet temperature (in the sense i am recircuilating the water), how would i be doing it? is it possible to update the value of the

问题 Some settings in Dymola can be altered by setting flags in the "Commands" window: Some examples for flags are: Advanced.AutoFormatting Advanced.PedanticModelica Advanced.LogStartValuesForIterationVariables Hidden.PrintFailureToDifferentiate Is there a comprehensive list of all Dymola flags? Or, even better, a command to print such a list? Or, even better, something like the about:config in Firefox? Especially, I would like to change the default setting for the Save contents in one file

问题 Given a python script that triggers simulations in the Dynamic Modeling Laboratory (Dymola). My goal is to get the data of the trajectories of my simulation, but in different sampling intervals. E.g. I want the transient section from 0 sec to 1000 sec to be sampled in 1sec intervals and the steady state section from 1000sec to 100000sec to be sampled in 100sec intervals without having to perform two simulations with different start times, stop times and output intervals. An excerpt of the

问题 I am currently developing a python interface for running Modelica simulations using Dymola and I can't find any documentation on the data types used in the dsin.txt file : ... 0 0 0 0 4 328 # timeToEmpty -1 0 0 100 2 272 # level 0 0 0 0 3 256 # der(level) -1 10 0 0 1 280 # initialFlowRate 0 0 0 0 6 320 # flowRate ... There is some documentation inside the file itself, but it's not very helpful : ... # column 6: Data type of variable. # = 0: real. # = 1: boolean. # = 2: integer. ... As you can

问题 I am an OpenModelica beginner trying to model a DC/DC converter with constant voltage and current limiting. Basically the output is supposed to give a constant voltage until the maximum current is reached and then hold that current by reducing voltage. This is the equation part of my code so far: model DC_DC "Voltage source with current limiting" import SI = Modelica.SIunits; parameter SI.Voltage Vnom(start=1) "Value of nominal output voltage"; parameter SI.Current Inom(start=1) "Value for

问题 I am an OpenModelica beginner trying to model a DC/DC converter with constant voltage and current limiting. Basically the output is supposed to give a constant voltage until the maximum current is reached and then hold that current by reducing voltage. This is the equation part of my code so far: model DC_DC "Voltage source with current limiting" import SI = Modelica.SIunits; parameter SI.Voltage Vnom(start=1) "Value of nominal output voltage"; parameter SI.Current Inom(start=1) "Value for

问题 This is a companion question to External Functions: Reference headers in C-script to compiled dll. That stack overflow question is using a Modelica external function call to a c-script. That c-script then uses c-functions contained within a .dll. Below is the initial preferred method I had attempted and a working attempt that I do not prefer. Initial Attempt: The following code would not work. My assumption was since I loaded the .dll Library libgsl in Modelica I could then simply use headers

问题 Using Dymola 2017. Case A) Calling an external c-script I have had success implementing simple external c functions that have no “# include <-->” statements: Modelica Function: function chirp input Modelica.SIunits.AngularVelocity w_start; input Modelica.SIunits.AngularVelocity w_end; input Real A; input Real M; input Real t; output Real u "output signal"; external "C" u=chirp(w_start,w_end,A,M,t) annotation(IncludeDirectory="modelica://ExternalFuncTest/Resources/Source/", Include="#include \

问题 I am attempting to define the parameter of a model (block) as a variable. For example: Real WallThickness = 0.5; Real WallConductance = 10*WallThickness; Modelica.Thermal.HeatTransfer.Components.ThermalConductor TopPanelConductor(G=WallConductance); I would like to define "G" so that it remains constant throughout the simulation but the coefficient is updated prior to the simulation based on the other variable "WallThickness". When defining the ThermalConductor parameter "G" as a variable in