AIAA Engine Design Team

miniDragon-950

Project

• Background
  • The purpose was to create a gas turbine generator for a hybrid electric UAV that performs better than the existing TPE331-10
• Cycle
  • The miniDragon-950 produces 949 horsepower with a Brake Specific Fuel Consumption of 0.33
  • Improvements were made through the use of more compressor and turbine stages and the addition of a recuperator
  • The largest improvement was the reduction of weight from 385 lbs to 148 lbs
• Configuration: 3-stage centrifugal compressor
  • Allows for a wide range of pressure ratios at similar efficiencies
  • Provides a sufficiently wide operational envelope to allow for varied flight speeds and altitudes
  • Is light and compact relative to a comparable axial-flow compressor
• Design Process
  • Used AxSTREAM (commercial software) to perform initial design at specified design condition, focused on minimizing required power input for a given
  • Two- and three-stage centrifugal compressor configurations were explored, the three-stage configuration is more efficient than the two- stage; axial-flow configurations were not considered due to weight and size
  • Created a 1D mean line analysis tool in Python to estimate the performance characteristics of the compressor at off-design conditions

Compressor and Inlet

• Configuration: 3-stage centrifugal compressor
  • Allows for a wide range of pressure ratios at similar efficiencies
  • Provides a sufficiently wide operational envelope to allow for varied flight speeds and altitudes
  • Is light and compact relative to a comparable axial-flow compressor
• Design Process
  • Used AxSTREAM (commercial software) to perform initial design at specified design condition, focused on minimizing required power input for a given
  • Two- and three-stage centrifugal compressor configurations were explored, the three-stage configuration is more efficient than the two- stage; axial-flow configurations were not considered due to weight and size
  • Created a 1D mean line analysis tool in Python to estimate the performance characteristics of the compressor at off-design conditions

Combustor

• configuration
  • The combustor is the heat addition portion of the power cycle, its purpose is to add as much energy to the system as other constraints allow
  • Reverse annular combustor geometry allows low pressure losses and maximizes total combustion volume per unit length
• Technology
  • Twin Annular Premixing Swirler technology (TAPS) will minimize harmful emissions and ensure the most efficient combustion
  • Ceramic Matrix Composites (CMC) for the combustor liner will allow high combustion temperatures. CMC materials also provide a 60% weight savings over alternative super-alloys
  • Additional liner cooling will come through angled effusion cooling. This method maximizes cooling surfaces while minimizing the internal airflow disruption

• Configuration: 5-stage axial turbine
  • Maximum efficiency occurs when the fluid does not swirl through the turbine section
  • Constructed with Silicon Carbide composite this material has high heat tolerance, great strength, and durability, and is light weight
• Design Process
  • AxSTREAM modeling software was used to determine the most efficient configurations for maximum power output