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• Engine Modelling

Engine performance characteristics are modelled as data matrices and can be 'rubberized', i.e. adjusted to any thrust level (sea-level-static or arbitrary reference value FN*). The user can choose one of many built-in types, or provide his own engine information.

The database supplied with Piano covers more than 30 engine models representing various propulsive systems including turbofans, turboprops, ducted fans and a propfan. Normalised thrust data have been derived from actual operational engines and reliable project simulations using a variety of sources. This collection constitutes a set of generic engines typical of modern commercial aircraft. Each engine can be used by several different aircraft, scaled to match a specific SLS thrust, ratings structure and fuel efficiency. Typical installed performance is given.

Maximum takeoff (MTO), max climb (MCL), max cruise (MCR) and max continuous (MCO) thrust ratings are represented individually as functions of altitude and Mach number. Fuel Flow or SFC (specific fuel consumption) characteristics are modelled in one of two ways: A single data matrix can cover all Mach/throttle combinations and is adjusted for altitude using a standard form, with optional corrections for small deviations. Alternatively, comprehensive information supplied by an engine manufacturer (a so-called 'Engine Deck') can be input, with individual 'SFC loops' at each altitude. The idle thrust and idle fuel flow are also covered.

A powerful 'Deck Filter' is used to extract, sort, and normalise information from the tabulated engine decks commonly found in industry.

Using a simple text format makes it easy to transfer and edit engine characteristics with minimal manipulation. Some facilities for spreadsheet-like data handling are also built into Piano. Smooth or linear data interpolation and extrapolation options are available.

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