TurbopropEngine

Yadav Khagendra k.M-tech (AME)Hindustan University

Introduction

A turboprop engine is a turbine engine that drives an aircraft propeller.

Propeller -90 percent of the total thrust.

Jet thrust -usually10 percent.

There are two basic types of turboprop engines:

1. Single shaft

2. Free turbine

The propeller is driven by the same shaft (spool) that drives the compressor.

1, Single-shaft turboprop engine

The propeller is driven by a dedicated turbine. A different turbine drives the compressor; this turbine and its compressor run at near-constant RPM regardless of the propeller pitch and speed.

2, Free-turbine turboprop engine

Current enginesmanufacturer Country Application

DEMC China Harbin SH-5, Xi'an Y-7

Europrop International European Union Airbus A400M

General Electric, LHTEC, Honeywell

United States Jetstream, Dornier

Pratt & Whitney Canada ATR, Bombardier, Beechcraft, cessna

KKBM, OMKB, RKBM, Rybinsk, Saturn

Russia Antonov

Progress Ukraine Antonov

PZL Poland PZL M28

Rolls-Royce United Kingdom Lockheed Martin

Turbomeca France Socata TB 31 Omega

Walter Czech Republic Let L-410 Turbolet UVP-E

Why use turboprop

The amount of power available for propulsion is largely independent of the forward speed of the aircraft, so that more power is available during the initial stages of the takeoff run.

A slipstream is produced behind the propeller that improves elevator and rudder control at low speeds.

The engine can be run under more efficient and economical conditions at low and medium altitudes, and retains these two qualities at low aircraft speeds.

Operations can be conducted from shorter runways.

fuel efficient.

Turboprop and Turbofan propulsive efficiency

Comparison of fuel consumption

Fuel consumption per passenger 370km stage length

Pilot salaries and fuel costs

Airline operators are investing more money in pilot salaries and fuel cost in jet engine aircraft as they burn more fuel in comparison to turboprop aircraft.

Airport tax are higher for larger aircraft with high MTOW then the smaller aircraft with low MTOW.

TAX

Operating costs

Bombardier Dash 8