April 22, 2006
AFT Engineering Utility Suite 2.0
Engineering Utility Suite has been a favorite tool for years, providing eight utilities that piping system engineers find useful almost every day –
- Compressible flow pipe sizing
- Incompressible flow pipe sizing
- Friction factor calculator
- Reynolds calculator
- ASME Nozzle, Orifice, Venturi Sizing
- Heat Transfer Coefficient Calculator
- Two-Phase Flow Map Utility
- Thermal/Fluid Engineering Unit Converter
Version 2.0 freshens up this popular tool with an improved interface and performance. Information, views, pricing and links to working demos will be found here.
Tips - Compressor Efficiency
Efficiency of a pump or compressor has a direct effect on the absorbed power. Unlike pumping liquids, however, compressor efficiency also has a direct effect on discharge conditions and the resulting resistance to flow downstream. Neglecting these can result in significantly under calculating the pressure drop in a gas flow system. AFT Arrow offers three choices for modeling compressor or fan efficiency; adiabatic, polytropic and ‘determine from efficiency data’.
Adiabatic compression is the equivalent of a 100% thermally efficient compressor and will yield the minimum temperature rise and thus the maximum discharge density and minimum downstream flow resistance for a given pressure rise across the compressor. Useful for initial estimates but, unfortunately, no one is as yet offering 100% efficient compressors!
With the polytropic option one can directly enter the polytropic exponent of compression for the compressor, which will always be greater than the adiabatic exponent which is a function only of the fluid.
With the ‘determine from efficiency data’ option chosen, AFT Arrow will calculate the polytropic exponent of compression from the compressor efficiency data you’ve entered. For a fixed flow or fixed head/pressure rise, a ‘nominal’ efficiency may be entered – a single point estimate of the compressor’s efficiency. When modeling the compressor with a curve, efficiency may be specified as a function of flow so that the compression exponent will vary according to where the compressor is operating on its curve.