.TRANSFORM.Fluid.System

Information

A system component is needed in each fluid model to provide system-wide settings, such as ambient conditions and overall modeling assumptions. The system settings are propagated to the fluid models using the inner/outer mechanism.

A model should never directly use system parameters. Instead a local parameter should be declared, which uses the global setting as default. The only exceptions are:

• the gravity system.g,
• the global system.eps_m_flow, which is used to define a local m_flow_small for the local m_flow_nominal:

  m_flow_small = system.eps_m_flow*m_flow_nominal

The global system.m_flow_small and system.dp_small are classic parameters. They do not distinguish between laminar flow and regularization of zero flow. Absolute small values are error prone for models with local nominal values. Moreover dp_small can generally be obtained automatically. Consider using the new system.use_eps_Re = true (see Advanced tab).

Contents

Name	Description
Medium	Medium model for default start values