Session: 01-14: Whole Engine Performance and Novel Concepts I

Submission Number: 177141

The Backbone Method for Compressor Maps 

This paper provides a thorough treatment of the formulation and use of the backbone map method for performance maps of axial compressors in gas turbine engines and aero-derivative applications. The backbone method has been in use at GE Aerospace for nearly 50 years and provides a physics-based method for describing compressor performance. This is in contrast to R-line or Beta maps which simply tabulate compressor performance with no regard for the underlying physics. The backbone method characterizes compressor performance in terms of normalized energy, loss, and flow. Of particular note is the use of loss, rather than efficiency, to evaluate compressor performance. The term backbone refers to the locus of points (as a function of speed) where compressor loss is minimized and is synonymous with the phrase min-loss (minimum loss). Performance at all other conditions is known as off-backbone performance. Off-backbone pressure ratio and efficiency are characterized by loss and energy deltas relative to the compressor backbone, while off-backbone flow is characterized by a pseudo-Mach number distribution along each speed line. A backbone map, therefore, is comprised of a set of tables that describe performance along the backbone, along with a second set of tables that describe performance off-backbone. The aim of this paper is to provide a more detailed derivation and description of the backbone method than has previously been seen in the literature.

Presenting Author: Robert Clark GE Aerospace

Presenting Author Biography: Dr. Robert Clark is a Staff Engineer in Performance Engineering at GE Aerospace. He attended Purdue University, receiving a BS in Mechanical Engineering. At GE Aerospace he completed the Edison Engineering Development Program, receiving an MS in Mechanical Engineering from The Ohio State University. Dr Clark spent time in cycle preliminary design before returning to school to pursue his PhD in aerospace engineering at the Georgia Institute of Technology. His thesis focused on the preliminary design of variable cycle engines, with an emphasis on variable geometry scheduling and integration of thermal management systems into the design process.

Authors:

Robert Clark GE Aerospace
Ronald Plybon GE Aerospace