This document describes a turbomachine neutral data format (NDF) for defining an overall machine geometry, topology, and operating conditions. The intent is to provide a mechanism for third party developers to export a neutral (that is, solver independent) description of the system from which the simulation environment can construct a complete simulation model.

The neutral data format was introduced as a means of transferring blade design information between applications in a manner that preserves the original design intent (meridional profile, angle and thickness distributions, or airfoil profiles), as opposed to the resulting 3D surface shape. Applications can use the NDF to reconstruct geometric components of a 3D turbomachine accurately and efficiently.

As detailed below, the turbomachine NDF contains an <ndf-blade-design> element. The <ndf-blade-design> element contains an optional <general-information> element followed by a required <ndf-definition> element. The <ndf-definition> element contains an optional <meridional-plane> element followed by an optional <flow-path> element followed by an optional <bladerow-objects> element. The <bladerow-objects> element contains one or more <bladerow> elements.