The best explanation of the PW 100 engine and its parts

The PW 100 engine series is at the forefront of modern, state-of-the-art regional and commuter turboprop engines. With its three-spool design, easy-to-maintain modular construction, and high power rating, the engine is a logical choice for midsize and large turboprops, including the Bombardier Q400, DeHavilland Dash 8, and Embraer EMB 120. The PW 100 is considered by some to be the replacement. . to the venerable PT6, but really the PW 100 picks up where the PT6 Large version left off in terms of power, fuel economy and reliability. The PW 100 series consists of a number of variations. There is no real PW 100 engine; the engines start with the PW118 engine and end with the PW127J.

The engines are essentially the same, with, for the most part, a steady increase in power output, as well as slight variations in engine output speed and mechanical vs. shaft horsepower ratio. thrust produced. In other words, each turboprop is rated in Equivalent Shaft Horsepower (eshp), which is a combination of the actual mechanical horsepower provided at the output shaft combined with the amount of horsepower available as a conversion from the engine. thrust produced in the exhaust pipe. The ratio varies, but is typically in the range of 80% power produced by the propeller, 20% produced by the tailpipe.

The Powerful Model PW 100 Engine is completely modular in construction; that is, it is made up of a series of interchangeable modules that can be easily removed and replaced in case there is a problem with the engine. The modules consist of the turbomachine, power turbine assembly, inlet casing, and output reduction gearbox. The compact turbomachine consists of the double coil gas generator and the accessory gearbox. The power turbine connects to the rear of the turbomachine and features a two-stage power turbine driving a shaft that runs to the center of the turbomachine shafts. The intake housing mounts to the front of the turbomachine and provides the clearance for air to enter the compressor and support for the output reduction gearbox. The output reduction gearbox mounts to the front of the input housing and takes the high-speed input from the power turbine shaft and converts it into a high-torque, low-rpm output drawn from the output flange. the propeller in front of the gearbox.

Atmospheric air is drawn in through the engine nacelle behind the propeller into a passive particle separator, which is part of the nacelle. Clean intake air is drawn upward into the downward-facing scroll-type engine inlet. The single-stage centrifugal compressor feeds air into the turbomachine. Air is accelerated outward by the compressor and fed into numerous curved diffuser ducts that smoothly deposit the airflow onto the face of the single-stage, high-pressure centrifugal compressor. The high pressure compressor raises the pressure to a design pressure ratio of almost 15:1 on some of the latest models. The high-pressure compressor feeds the airflow into a diffuser that converts dynamic pressure to static pressure as it enters the reverse-flow annular combustor. Compressed air enters the inner combustion liner where it is mixed with jet fuel and ignited. The resulting gas expands through the high-pressure nozzle to impinge on the single-stage axial high-pressure turbine, which drives the high-pressure compressor and auxiliary gearbox. The gas is then further expanded through the low-pressure nozzle to drive the low-pressure turbine, which drives the low-pressure compressor. Finally, the gas expands through the two-stage power turbine to drive a concentric shaft to the front of the engine, which drives the output reduction gearbox. The exhaust is then directed out of the short axial flow, fixed area exhaust outlet to provide nearly 2,000 lbs. thrust on some popular PW-100 engine models. The output reduction gearbox reduces the speed of the power turbine to a usable 1,200 or 1,300 rpm, to drive a four-blade constant-speed propeller. Accessories include a generator, oil pumps, fuel pumps, hydraulic pumps and a FADEC fuel control.

The dual spool compressor offers many advantages over a similar single spool compressor. By allowing the two compressors to run at different speeds, the compressors can optimize a wide range of airflows. This allows for a higher design pressure ratio, much better part power efficiency and very fast engine response. High pressure ratios and high turbine inlet temperatures allow for very low specific fuel consumption, and advanced cooling techniques and state-of-the-art materials allow for a long period between overhaul periods.

There are a couple of other variants of the PW 100 worth mentioning. The PW150 engine is a high-powered development of the PW 100; It is very similar in general design and dimensions to the PW 100, except that the low pressure compressor is a single stage axial followed by a single stage centrifugal. The pressure ratio is over 18:1 and the engine produces power in the 5000 es-hp class, making it a suitable replacement for the Allison T56 or an alternative to the Rolls Royce AE1107C. There are also turboshaft versions of the PW 100, in which the input and output reduction gearbox is removed and replaced with a protected flare-mouth inlet and carrier bearing. Engine output is at power turbine speed. The engine could be an alternative to the CT7 (T700) turboshaft in medium-sized helicopters, although it has not been used in this application so far. However, there is a marine variant of this turbo shaft available for modern surface effect military ships. These models are called ST18M. Power output is approximately 3,200 shaft horsepower.