On 13 April prof. E. Spisak from TUK talked about the field of transport phenomena as the basis of modeling in polymer processing. This workshop lecture presented the derivation of the balance equations and combined them with constitutive models to allow modeling of polymer processes. The chapter also presents ways to simplify the complex equations in order to model basic systems such as flow in a tube or Hagen- Poiseulle flow, pressure flow between parallel plates, flow between two rotating concentric cylinders or Couette flow, and many more. These simple systems, or combinations of them, can be used to model actual systems in order to gain insight into the processes, and predict pressures, flow rates, rates of deformation, etc. When solving flow and heat transfer problems in polymer processing, the conservation of mass, forces or momentum and energy must be satisfied. Momentum and energy balances, in combination with material properties through constitutive relations, sometimes result in governing equations that are highly non-linear. This chapter presents the balance equations, making use of constitutive relations presented in this lecture.
