System Poly:- computes polytropic expansion temperature.

Parameter: alpha = (n-1)/n (n = polytropic index) This four-port component computes the temperature following a polytropic expansion using where alpha = (n-1)/n and n is the coefficient of polytropic expansion. This component imposes zero flow at all its ports and therefore does not affect energy balance. The output is bicausal as it imposes both T_2 and a zero flow. This is implemented using the bicausal SS component labeled ``zero''.