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Over 20 years ago I modeled an internal combustion engine, an automatic transmission and a multibody chassis model all in a single model. IIRC, the model had s

Over 20 years ago I modeled an internal combustion engine, an automatic transmission and a multibody chassis model all in a single model. IIRC, the model had something like 250,000 equations in it and it modeled combustion, hydraulics, friction, and 3D rigid body motion. It is capable of far more than simple models. https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=2234d4c76767d2609df20bfff4a31b7e794d4531 https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&d...

bobim 2y ago
Ah! You're the author of Modelica by example?
- michaeltiller 2y ago
  Yes. And "Introduction to Physical Modeling with Modelica". I also built the Modelica Playground (which I deliberately didn't link to because a thundering herd of HN readers would have crashed it).
  - bobim 2y ago
    Nice to cross your path, I got the first one to kickstart myself some years ago (and still struggling with evaporation / condensation). Would you recommend the second to introduce a colleague to OpenModelica? He is into gPROMS but will lose access to the software at retirement. Sidenote: invest in software with freedom to operate and good knowledge reusability.
    - michaeltiller 2y ago
      Modelica by Example is the most recent and free, so I would recommend that.
  - dr_kiszonka 2y ago
    Are you aware of any books like your "Introduction to Physical Modeling with Modelica" but for readers without a background in EE, math, physics? I am looking for something for a mediocre SWE like myself. It doesn't have to be Modelica; I could try learning MatLab or Mathematica, etc.
    - michaeltiller 2y ago
      Well if you are interested in the intersection of software engineering and technical computing, I'd recommend Julia. I'm currently working on JuliaSim which is a Modelica like system built on top of Julia. So Julia might interest you as a programming language and then you could pick and choose what aspects of things like ModelingToolkit if you are interested in the engineering, math and physics aspect or you can just stick to the software/programming aspects of Julia.
standeven 2y ago
That’s incredible, I had no idea this was even possible. Are most auto manufacturers modelling their vehicles this way? Seems like an amazing way to search for optimizations, predictive failures, etc.
- michaeltiller 2y ago
  It is pretty wide spread in automotive. I think nearly all F1 teams use it (hard to know for sure since they are quite secretive, but it is very common in my experience)

bobim 2y ago

Ah! You're the author of Modelica by example?

michaeltiller 2y ago
Yes. And "Introduction to Physical Modeling with Modelica". I also built the Modelica Playground (which I deliberately didn't link to because a thundering herd of HN readers would have crashed it).
- bobim 2y ago
  Nice to cross your path, I got the first one to kickstart myself some years ago (and still struggling with evaporation / condensation). Would you recommend the second to introduce a colleague to OpenModelica? He is into gPROMS but will lose access to the software at retirement. Sidenote: invest in software with freedom to operate and good knowledge reusability.
  - michaeltiller 2y ago
    Modelica by Example is the most recent and free, so I would recommend that.
- dr_kiszonka 2y ago
  Are you aware of any books like your "Introduction to Physical Modeling with Modelica" but for readers without a background in EE, math, physics? I am looking for something for a mediocre SWE like myself. It doesn't have to be Modelica; I could try learning MatLab or Mathematica, etc.
  - michaeltiller 2y ago
    Well if you are interested in the intersection of software engineering and technical computing, I'd recommend Julia. I'm currently working on JuliaSim which is a Modelica like system built on top of Julia. So Julia might interest you as a programming language and then you could pick and choose what aspects of things like ModelingToolkit if you are interested in the engineering, math and physics aspect or you can just stick to the software/programming aspects of Julia.

standeven 2y ago

That’s incredible, I had no idea this was even possible. Are most auto manufacturers modelling their vehicles this way? Seems like an amazing way to search for optimizations, predictive failures, etc.

michaeltiller 2y ago
It is pretty wide spread in automotive. I think nearly all F1 teams use it (hard to know for sure since they are quite secretive, but it is very common in my experience)