eaching Modelica for Engineers at echnische Universität Braunschweig W. egethoff, M. Gräber, R. Kossel, C. Richter University of Braunschweig Institute of echnology
Contents. Classroom and Exam. hinking in Objects 3. Course Example: Refrigeration Cycle 4. Course Example: ire Service Garage 5. Course Example: Lumped Capacitors 6. Conclusion echnische Universität Braunschweig
Classroom Willi 4 Course Hours Manuel 3 echnische Universität Braunschweig
Final Exam Learning targets: Modeling language Modelica Numeric for solving DAE-Systems (heuristic) Object-oriented analysis 4 echnische Universität Braunschweig
Final Exam Exam ime: 30 Minutes What is Polymorphism? 5 echnische Universität Braunschweig
Contents. Classroom and Exam. hinking in Objects 3. Course Example: Refrigeration Cycle 4. Course Example: ire Service Garage 5. Course Example: Lumped Capacitors 6. Conclusion 6 echnische Universität Braunschweig
hinking in Objects What is a class? What is an object? Class: Construction Plan / Blueprint Instantiation: Building Object: he house More objects of the same class Modifier 7 echnische Universität Braunschweig
Object-oriented Analysis Animal is a a is part of 8 echnische Universität Braunschweig
Object-oriented Analysis Animal is a a 6 4 4 is part of 9 echnische Universität Braunschweig
Object-oriented Analysis 0 echnische Universität Braunschweig
Overview of Course Examples Refrigeration Cycle ire Service Garage Lumped Capacitors echnische Universität Braunschweig
Contents. Classroom and Exam. hinking in Objects 3. Course Example: Refrigeration Cycle 4. Course Example: ire Service Garage 5. Course Example: Lumped Capacitors 6. Conclusion echnische Universität Braunschweig
Refrigeration Cycle 3 echnische Universität Braunschweig
Solving Non-linear Algebraic Equations gascooler.idealoutletrefrigerant.p = E+007 receiver.refrigerant.p = 0 Residual: { -0.065439, 99.9 } gascooler.idealoutletrefrigerant.p = -E+009 receiver.refrigerant.p = -.4559 Residual: { -0.04, -904.99 } gascooler.idealoutletrefrigerant.p = -9.783E+008 receiver.refrigerant.p = -.8344 Residual: { -0.0970766, -904.99 } 4 echnische Universität Braunschweig
Solving Non-linear Algebraic Equations Newton s s Method 5 echnische Universität Braunschweig
Solving Non-linear Algebraic Equations Pitfalls: 6 echnische Universität Braunschweig
Contents. Classroom and Exam. hinking in Objects 3. Course Example: Refrigeration Cycle 4. Course Example: ire Service Garage 5. Course Example: Lumped Capacitors 6. Conclusion 7 echnische Universität Braunschweig
ire Service Garage ire Service Garage 8 echnische Universität Braunschweig
ire Service Garage ire Service Garage Car <<partial>> ire Firestone Michelin 9 echnische Universität Braunschweig
ire Service Garage Car Icon Object Diagram 0 echnische Universität Braunschweig
ire Service Garage Car model Car Firestone spareire; Michelin frontrightire; Michelin frontleftire; Michelin backrightire; Michelin backleftire; end Car; Object Diagram echnische Universität Braunschweig
ire Service Garage Car model Car replaceable Firestone spareire extends ire annotation (choicesallmatching=true); replaceable model iremodel = Michelin extends ire annotation (choicesallmatching=true); iremodel frontrightire; iremodel frontleftire; iremodel backrightire; iremodel backleftire; end Car; Object Diagram echnische Universität Braunschweig
ire Service Garage ire Service Garage M M redeclare model iremodel = Michelin; 3 echnische Universität Braunschweig
Contents. Classroom and Exam. hinking in Objects 3. Course Example: Refrigeration Cycle 4. Course Example: ire Service Garage 5. Course Example: Lumped Capacitors 6. Conclusion 4 echnische Universität Braunschweig
5 Lumped Capacitors s R R Q dt d C Q Q dt d C = = Q Q C C R Q R Q s = = R C dt d R C R C dt d s = = echnische Universität Braunschweig
Euler s Method 380 emperature [K] 360 340 30 Euler s s Solution Dassl s Solution 300 ime [s] 0 0 0 30 40 50 6 echnische Universität Braunschweig
Lumped Capacitors - Stiffness 6.0 e8 emperature [K] 0 ime [s] -6.0 e8 0 00 400 600 800 000 7 echnische Universität Braunschweig
Lumped Capacitors - Stiffness R >> R s R R C C 8 echnische Universität Braunschweig
Lumped Capacitors - Stiffness 400 emperature [K] 350 Euler s s Method Δt t = e-4 4 sec 300 ime [s] 0 4 6 8 0 9 echnische Universität Braunschweig
Lumped Capacitors Index Reduction s R C C d dt d dt Q Q = = s R R 30 echnische Universität Braunschweig
Lumped Capacitors State Selection s R C C 3 echnische Universität Braunschweig
Contents. Classroom and Exam. hinking in Objects 3. Course Example: Refrigeration Cycle 4. Course Example: ire Service Garage 5. Course Example: Lumped Capacitors 6. Conclusion 3 echnische Universität Braunschweig
Conclusion Students typically have to learn thinking in objects Students learn modelling in Modelica by Carefully selected didactical concepts Well assisted assignments Final projects In thermo-fluid systems, good knowledge about numerical solving of DAE-Systems is necessary 33 echnische Universität Braunschweig