Tutorial 2: Single Stage Centrifugal Compressor
Design a single stage radial compressor using Compal software of
ConceptsNREC, for this purpose, you need to choose File/New and go
through the steps in order to input the data needed for the design.
Choose Concepts two-zone model
Choose the Mode Design to operate the solver, then single stage. Metric
units, Blank Template.
Inlet Conditions are
P00: 101 KPa, T00: 310 K, Mass flow rate: 5 kg/s
Rotational speed: 30000 RPM, choose ideal gas or semi perfect air as
operating fluid.
Design total-to-total pressure ratio = 2.5
3D wheel option
You can either specify the hub radius or hub to tip radius ratio for impeller
Geometry at inlet: R1h/R1t = 0.7, you can keep the default inlet and outlet
phi equal to 90 degrees.
Inlet incidence angle for three spanwise locations of tip, RMS and hub are
one degrees.
Thickness of leading edge at shroud = 2 mm, please specify the
dimensions noting the units that you have chosen at units section.
Number of vanes at inlet can be chosen 7.
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You can choose a 2D wheel, well designed inlet.
You can choose an open impeller with front and tip clearances of 1 mm.
Back sweep angle can be -45 degrees.
One splitter vane per passage, therefore vane number increases to 14.
For the limited scope of this tutorial, keep default values of Lambda,
secondary and deviation modes, if you want to know more and change
their values, click on Help and read what they refer to.
You can choose a cascade diffuser type.
Make realistic guesses for radius ratios of the diffuser. Enter number of
vanes for diffuser.
Velocity ratio = 1.1 and keep the default blockage of 0.035.
Thickness of blades 3mm.
Plot the velocity triangles at the inlet and outlet of the impeller of the
compressor. If there are error messages, you can go through the Wizard
and check/change the inputs. Click on the TextReport in the toolbar in
order to get output information of the designed compressor at various
cross sections. Upload the text report in Canvas together with the velocity
triangles and a sketch of the designed compressor.
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