Class Example / Notes

1. Primary Cycle Parameters Optimized to Minimize Fuel Consumption and Maximize Power Overall Pressure Ratio (OPR or P3QP2) Cycle Temperature (RIT or T4) Engine “Sized” to Meet Power Demands (Design Point) Inlet Flow (Wc) Set to Match Power Requirement Note – Sizing is Direct Driver on Weight Generally Speaking Increasing T4 Reduces Engine Size for a Given Power Requirement Increasing OPR Reduces Fuel Consumption To a Point, then the Trend Reverses Component Efficiencies Strongly Influence These Trades Same Holds for Cooling Air, Parasitic Losses, etc. Class Example / Notes Single Spool Turboshaft – Overview

2. Construct and Execute a Cycle for the Following T4 = 2000° R, OPR = 12, 100#/s Wc Baseline Component Efficiencies =85% (HPC and HPT) Burner Pr Loss = 5%, Nozzle PR = 1.05 What Flow is Required to Produce 10000 SHP What is the Impact of Changing T4 +500° What About Increasing Component Efficiency 5% Class Example / Notes Single Spool Turboshaft – Example 1 Wc OPR Burner Pr Loss T4 Nozzle PR

3. Reset the Base Cycle Conditions T4 = 2000° R, OPR = 12 100#/s Wc Baseline Component Efficiencies =85% Burner Pr Loss = 5%, Nozzle PR = 1.05 Add Automatic Iteration to Vary Flow to Hold Power Constant Sweep T4 from 2000° to 3000° in Increments of 250° Sweep OPR from 12 to 20 in Increments of 2 Redo with 90% Component Efficiencies Class Example / Notes Single Spool Turboshaft – Example 2 Wc OPR Burner Pr Loss T4 Nozzle PR

4. Lets Examine the Impact to Fuel Consumption and Sizing Class Example / Notes Single Spool Turboshaft – Example 2 Results 85% Component Eff 90% Component Eff 2500° T4 12 OPR 2000° T4 12 OPR 20 OPR 2500° T4 3000° T4

5. Design Mode Engine Components Sized to Meet Continuity and Power Balance Continuity  Exit Corrected Flow of Component = Inlet Corrected Flow of Next Component Area Sized to Ensure Continuity Power Balance  Work of Turbine = Work of Compressor + Loads Expansion Ratio of Turbine Set to Meet Power Demands Off-Design Mode Areas are Fixed Continuity Sets the Match of the Compressor Turbine Expansion Ratio and Speed Vary to meet Power Demand Class Example / Notes Single Spool Turboshaft – Off Design Matching

6. Design Point Operation (Areas Sized for Contiuity) Iteration Variable Target Variable (Independent) (Dependent) Vary Wc Inlet to get SHP Load (user input / user defined balance) Vary Load to get Zero Net Torque (power balance / automatic) Vary P/P HPT to get Nozzle P/P (desired value / automatic) Vary Wfuel to get T4 (user input / power management) Class Example / Notes Single Spool Turboshaft – Solution Matrix Definition • Off-Design Operation (Areas Known) • Iteration Variable Target Variable • (Independent) (Dependent) • Vary Wc Inlet to get Continuity HPC (map / automatic) • Vary Op-Line HPC to get Continuity HPT (map / automatic) • Vary P/P HPT to get Continuity Nozzle (compressible flow / automatic) • Vary Wfuel to get T4 (user input / power management) • Vary Nshaft to get Nshaft (user input / automatic)

7. Reset the Base Design Point T4 = 2000° R, OPR = 12 100#/s Wc Baseline Component Efficiencies =85% Burner Pr Loss = 5%, Nozzle PR = 1.05 Confirm Off-Design Matches Design Point Lets Examine the Phenomena of Engine “Matching” Close the HPT Area 10% (use scale_hpt_area) What Happens to Compressor Flow and PR Why? Now Open the HPT Area 10% What Happens to Compressor Flow and PR Class Example / Notes Close HPT Area Base PR Open HPT Area Nc Wc Single Spool Turboshaft – Example 3