Paolo Stringari

A Fundamental Equation of State for Sulfur Hexafluoride (SF6) in Extended Equation of State Format

An innovative method for the regression of thermodynamic properties of pure fluids was recently proposed. The technique, indicated as an extended equation of state, adopts a framework similar to the extended corresponding states method, but a cubic equation is assumed instead of the equation of state of the reference fluid and the shape functions are expressed through a multilayer feedforward neural network. The use of a neural network assures a very high flexibility of the functional form to be regressed, so the resulting model reaches a representation accuracy which is comparable to that attained by the state-of-the-art multiparameter equations of state in the representation of the thermodynamic properties of a pure fluid. The technique was applied here to sulfur hexafluoride aiming at drawing its dedicated equation of state in a heuristic mode directly from the available experimental data. For sulfur hexafluoride (critical point is at Tc=318.7232K and Pc=3.754983MPa), experimental data of several prope...

A Fundamental Equation of State for 2-propanol (C3H8O) in the Extended Equation of State Format

An innovative method for the regression of a fundamental equation of state of a pure fluid was recently proposed. This technique, called an extended equation of state, adopts a framework similar to the extended corresponding states method but uses a cubic equation for the target fluid instead of the equation of state for the reference fluid, and shape functions are expressed through a multilayer feedforward neural network. The use of a neural network assures very high flexibility of the functional forms to be regressed, allowing the resulting model to represent the thermodynamic properties of a pure fluid with an accuracy comparable to that attained by state-of-the-art multiparameter equations of state. The technique is applied here to 2-propanol to derive a dedicated equation of state in a heuristic mode directly from the available experimental data. The majority of the data cover the range of temperatures from 280to600K and pressures up to 50MPa; this is also the validity range of the developed equation...