Reverse-Flow Turboshaft Engine Study

Abstract

The report presents the results of a program conducted to investigate the characteristics of a three-spool turboshaft engine having an unconventional turbine arrangement. In this engine, called a three-spool reverse-flow turboshaft engine, the combusted air passes through the high pressure (HP) turbine, then the power turbine, and finally through the low-pressure (LP) turbine. The performance, weight, envelope, and transient characteristics of this engine were compared to those of a more conventional two-spool turboshaft engine of comparable life and component technology. In addition, the suitability of the three-spool reverse-flow turboshaft engine for recuperation was assessed. The results of the study indicated that the three-spool reverse-flow turboshaft engine provides better part-power specific fuel consumption (SFC) than the two-spool engine. However, te engine is sensitive to ambient temperature variations, necessitating flat-rating of the engine to minimize the hot-day power lapse; is somewhat heavier; has a slightly larger envelope (length and diameter) and higher power-output speed; and requires approximately 3 seconds longer to accelerate from flight idle to 95 percent MRP. The reverse-flow engine component arrangement appears to have its greatest potential in a recuperated configuration.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1970
Accession Number
AD0877672

Entities

People

  • K. M. Johansen
  • W. H. Duncan

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Army Aviation
  • Calorific Value
  • Contracts
  • Control Systems
  • Engine Components
  • Flight Speeds
  • Flow
  • Fuel Consumption
  • Fuel Systems
  • Gas Turbines
  • Generators
  • Geometry
  • Heat Transfer
  • Standards
  • Turbine Components
  • Turbines
  • Turboshaft Engines

Fields of Study

  • Engineering

Readers

  • Aerospace Engineering
  • Mathematics or Statistics