modelica

问题 Suppose that I'd like to model an alarm clock that produces 10 beeps (one per second) every morning at 01:00: model DailyBeep import SI = Modelica.SIunits; import Modelica.SIunits.Conversions.*; constant SI.Time oneDay = 86459.17808 "one day in seconds"; parameter SI.Time startTime = from_hour(1) "time to start beeping"; parameter Real numBeeps = 10 "the number of beeps to make"; Boolean beeping "true when we should beep every second"; Real beepsRemaining "the number of beeps remaining";

问题 I have a model of a tank that I am creating as follows: model Tank "Simple model of a tank" parameter Real volume=1 "tank volume (m^3)"; parameter Integer num_ports=1 "Number of ports"; parameter Real static_pressure=1 "Internal Tank Pressure"; parameter Real initial_level = 0; Stream[num_ports] ports "Stream Connectors"; Real level "Level in % 0-100"; protected Real vol "Volume of medium in the tank"; Real pressure(start=static_pressure) "Pressure inside the tank"; initial equation level =

问题 I'm getting some strange behavior in a simple co-simulation that I'm trying to configure. I setup a building energy model in EnergyPlus to test out an FMU generated from JModelica. However, the building energy model would get hung up at the co-simulation step. I then ran the FMU in JModelica and got some very strange results. The Modelica code is: model CallAdd input Real FirstInput(start=0); input Real SecondInput(start=0); output Real FMUOutput(start=0); function CAdd input Real x(start=0);

问题 I'm trying to follow this example to generate a random function of time: model testData extends Modelica.Icons.Example; parameter Real k = 1.0; Real theta1; Real theta2; parameter Real tau = 1.0; parameter Modelica.SIunits.Period samplePeriod = 0.05; parameter Integer globalSeed = 30020; output Real omega1; algorithm when initial() then state1024 := Generators.Xorshift1024star.initialState(localSeed, globalSeed); omega1 := 0; elsewhen sample(0,samplePeriod) then (omega1,state1024) :=

问题 I am trying to build a model that can use two different components (taken from an existing library) for the same scope: in particular a system with an heat exchanger; this heat exchanger can be based on different technologies, e.g. pipes or plates. I want then define a model with a default replaceable exchanger and say which other technologies may be used. This is a vey simple exemple of what I tried: package Test // Component 1 original definition in the library model COMP1 parameter Real p1

问题 I've been working within the ThermoPower Library of OpenModelica for a while now trying to build a Combined Power Cycle by first modeling the Brayton and Rankine Power Cycles first. Every time I attempt to use a pump, I always receive errors like: [1] 10:31:00 Translation Error [ThermoPower.Examples: 2523:70-2523:81]: Variable q_nom not found in scope ThermoPower.Examples.RankineCycle.Models. [2] 10:31:00 Translation Error [ThermoPower.Examples: 2531:21-2531:69]: Cyclically dependent

问题 I'm building a Media-Library in Dymola similar to Helmholtz-Media but for Ammonia+Water, a mixture. You get a lot of not explicitly solvable equations. Because of the structure of the Media and Fluid libraries in Modelica I need to be able to get my thermodynamic state from p, h and x. The state-vector consists of d, T, and x. This is a simple example how to get the state-vector: model getState_phX parameter AbsolutePressure p = 500000 "pressure"; parameter SpecificEnthalpy h = 2500000

问题 I was wondering if there already exists a possibility to extract from flat Modelica code all variables AND their corresponding types (classnames respectively). For example: Given an extract from a flattened Modelica model: constant Integer nSurfaces = 8; constant Integer construction1.nLayers(min = 1.0) = 2 "Number of layers of the construction"; parameter Modelica.SIunits.Length construction1.thickness[construction1.nLayers]= {0.2, 0.1} "Thickness of each construction layer"; Here, the

问题 I can't really find any answer in the Modelica specification so ill ask you guys. The specification states that A tool is free to solve equations, reorder expressions and to not evaluate expressions if their values do not influence the result (e.g. short-circuit evaluation of Boolean expressions). If-statements and if-expressions guarantee that their clauses are only evaluated if the appropriate condition is true, but relational operators generating state or time events will during continuous

问题 Given a model with an array x of connectors where its size is unspecified, e.g. connector con ... end con; model test con x[:]; end test; How can x be instantiated with a specific size, e.g. something like this? test t(x = ?); ... equation connect(t.x[1], a); connect(t.x[2], b); ... 回答1: Why do you need unspecified dimension? You can do something like this: connector con ... end con; model test constant Integer dim = 1; con x[dim]; end test; // usage test(dim = 10); ... equation connect(t.x[1