.ThermoSysPro.Properties.Common.BridgmansTables

Information

Important: the phase equilibrium conditions are not yet considered.  
this means that Bridgman's tables do not yet work in the two phase region.  
Some derivatives are 0 or infinity anyways.  
Idea: Do not use the values in Bridgmans table directly, all  
derivatives are calculated as the quotient of two entries in the  
table. The last letter indicates which variable is held constant in  
taking the derivative. The second letters are the two variables  
involved in the derivative and the first letter is always a d to remind  
of differentiation.  


Example 1: Get the derivative of specific entropy s w.r.t. Temperature at  
constant specific volume (between identical to constant density)  
constant volume  --> last letter v  
Temperature      --> second letter T  
Specific entropy --> second letter s  
--> the needed value is dsv/dTv  
Known variables:  
Temperature T  
pressure p  
specific volume v  
specific inner energy u  
specific enthalpy h  
specific entropy s  
specific Helmholtz energy f  
specific gibbs enthalpy g  
Not included but useful:  
density d  
In order to convert derivatives involving density use the following  
rules:  
at constant density == at constant specific volume  
ddx/dyx = -d*d*dvx/dyx with y,x any of T,p,u,h,s,f,g  
dyx/ddx = -1/(d*d)dyx/dvx with y,x any of T,p,u,h,s,f,g  
Usage example assuming water as the medium:  
model BridgmansTablesForWater  
extends ThermoFluid.BaseClasses.MediumModels.Water.WaterSteamMedium_ph;  
Real derOfsByTAtConstantv "derivative of sp. entropy by temperature at constant sp. volume"  
ThermoFluid.BaseClasses.MediumModels.Common.ExtraDerivatives dpro;  
ThermoFluid.BaseClasses.MediumModels.Common.BridgmansTables bt;  
equation  
dpro = ThermoFluid.BaseClasses.MediumModels.SteamIF97.extraDerivs_pT(p[1],T[1]);  
bt.p = p[1];  
bt.T = T[1];  
bt.v = 1/pro[1].d;  
bt.s = pro[1].s;  
bt.cp = pro[1].cp;  
bt.alpha = dpro.alpha;  
bt.gamma = dpro.gamma;  
derOfsByTAtConstantv =  bt.dsv/bt.dTv;  
                ...  
end BridgmansTablesForWater;  
                  
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