All training

Generator Object Demonstration

intermediate
How to model a diesel generator in CoolSim external flow: front inlet, rear outlet, hot exhaust stack, grouping, and reading the exhaust plume.

This demonstration builds a diesel generator in a CoolSim external-flow model, using values from a manufacturer spec sheet. The point of the model is to see where the hot exhaust plume goes, for example into nearby heat exchangers.

What the video shows

  1. The spec sheet: the generator pulls air in through the front and discharges it at the rear, with a small, very hot exhaust stack on top. The two most important numbers are the exhaust flow rate and the stack temperature, about 900 degrees F in the example.
  2. Starting geometry: a box for the generator package, set in an external-flow room with wind.
  3. Front inlet: adding an inlet/outlet object (new in version 5), setting its axis and the air flow from the spec sheet, and naming it with a number so it can be found in the output. It is made slightly smaller than the box face, with a gap at the edges, because the mesher can move it off the surface and the model then fails to mesh. The Close Gaps tool then puts it flush with the face.
  4. Rear outlet: cloning the inlet across the box length, naming it, giving it the same flow rate and a temperature rise, 30 degrees in the demo.
  5. Stack: a rectangular block changed from a column to a general block, placed on top of the box, with a small exhaust outlet on top at the stack flow rate and temperature.
  6. Grouping the parts, so they appear together in the numerical report, and exporting the group as a CSO file or saving it to the library.
  7. Running the job and reading the results: group statistics, temperature path lines from the inlets and outlets, and extra temperature contour planes placed at the stack by reading coordinates from the cursor. A post-only rerun adds the planes without re-solving.

Tips

  • Leave room around each inlet and outlet, then close gaps.
  • Build the stack from blocks rather than ducts. Blocks can also form exhaust pipes that run up, over and out.
  • The presenter says the exhaust plume is the main concern: where it goes and whether it is pulled into an intake or a nearby heat exchanger.