<< Click to Display Table of Contents >> Dimensions 

The main dimensions of a rotor  inlet diameter dS1 and dH1 and outlet diameter dS2 and dH2  can be seen on Main dimensions panel. They can be recomputed by pressing the Calculatebutton. The computation is based on "Euler's Equation of Turbomachinery", on the continuity equation and the relations for the velocity triangles as well as on the parameters and parameter ratios given in the tab sheets Setup and Parameters. Individual main dimensions can be calculated separately using the button inside the value field. You may accept the proposed values or you can modify them slightly, e.g. to meet a certain normalized diameter. 
In case the checkbox Automatic is activated a new calculation will accomplished after any change of parameter. Then the manual alteration of the main dimensions is not possible.
Neighboring components
In specific cases the dimensions of the neighboring components at inlet and/ or outlet can be used to get exactly matching geometry.
This feature is available only for explicitly uncoupled components or sidebyside impellers.
In the right panel of any tab sheet an information panel is situated, which holds the computed variables in accordance to the actual state of design, the resulting Meridional section as well as the CordierDiagramm with the location of the best point. These three sections can be chosen by the appropriate soft buttons in the heading.
In the information section of the tab sheet Dimensions the following variables are displayed for Information:
Work coefficient 

Flow coefficient 


Meridional flow coefficient 

Specific diameter 

Inlet pressure, density and temperature 
p1, T1, ρ1, pt1, Tt1, ρt1, Q1, m1, s1 
static and total values 
Inlet velocities 
c1, cu1, cm1, w1, wu1, wm1, u1, Mac1, Maw1, Mau1, α1, β1 

Outlet pressure, density and temperature 
p2, T2, ρ2, pt2, Tt2, ρt2, Q2, m2, s2 
static and total values 
Outlet velocities 
c2, cu2, cm2, w2, wu2, wm2, u2, Mac2, Maw2, Mau2, α2, β2 

Isentropic velocity ratio 
only turbines 

Pressure rise coefficient 

only compressor 
Suction capacity 

only compressor 
The Meridional preview is based on the main dimensions designed until this point.
The Cordier diagram can be used for checking the impeller diameter d2.
See Cordier.
The Velocity triangles are the result of a midspan calculation and are based on the design point and the main dimensions.
Problem 
Possible solutions 

Thermodynamic state cannot be calculated at inlet/outlet. Possible reason: choked flow. The cuspecification will not be available. 

The dimensions might be too tight for the specified mass flow and inlet conditions. In other words the mass flow is higher than the choked mass flow rate for the particular inlet conditions and the respective cross section. 
Increase the dimensions (diameters etc.) or change the Global setup (e.g. decrease mass flow, increase pressure, decrease temperature). 