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*NETWORK MPC

Keyword type: model definition

With this option, an equation between variables in a network (total temperature and total pressure at the end nodes of a network element, mass flow in the middle node) can be created. The corresponding degrees of freedom are:

The use of *NETWORK MPC requires the coding of subroutines networkmpc_lhs.f and networkmpc_rhs.f by the user. In these routines the user defines the MPC (linear or nonlinear) using the information entered underneath *NETWORK MPC. The syntax is identical to *EQUATION except for an additional parameter TYPE specifying the type of MPC. Using this type the user can distinguish between different kinds of MPC in the networkmpc_lhs.f and networkmpc_rhs.f subroutines.

For instance, suppose the user wants to define a network MPC of the form:

$\displaystyle f:=a p_{t} (node_1) + b p_t^2 (node_2)=0$ (481)

specifying that the total pressure in node 1 should be (-b/a) times the square of the total pressure in node 2. There are 2 degrees of freedom involved: dof 2 in node 1 and dof 2 in node 2. Underneath *NETWORK MPC the user defines the coefficients and degrees of freedom of the terms involved:

*NETWORK MPC,TYPE=QUADRATIC
2
node1,2,a,node2,2,b

All this information including the type of the MPC is available in the networkmpc_lhs.f and networkmpc_rhs.f subroutines. In networkmpc_rhs.f the user has to code the calculation of -f, in networkmpc_lhs.f the calculation of the derivative of f w.r.t. each degree of freedom occurring in the MPC. This has been done and the reader is referred to the source code and example networkmpc.inp for further details.


next up previous contents
Next: *NO ANALYSIS Up: Input deck format Previous: *MPC   Contents
guido dhondt 2017-10-08