AixLib.Fluid.Movers.Compressors.Utilities.EngineEfficiency

# .AixLib.Fluid.Movers.Compressors.Utilities.EngineEfficiency

Package that contains models describing different engine efficiencies

## Information

This package contains models describing calculations procedures of engine efficiencies that are based on a literature review. However, in this library the engine efficiency is implemented in such a way that it fulfills
`ηeng = Q̇ref / Pel`.
For more information, please checkout AixLib.Fluid.Movers.Compressors.BaseClasses.PartialCompression.

#### Commen model variables

Calculation procedures presented in the litarture have some variables in commen and these variables are presented below:

"Inputs and outputs" border="1" cellspacing="0" cellpadding="2" style="border-collapse:collapse;">

Variable | Comment
--- | ---
`epsRef` | Ratio of the real and the ideal displacement volume
`VDis` | Displacement volume
`piPre` | Pressure ratio
`rotSpe` | Rotational speed
`staInl` | Thermodynamic state at compressor's inlet conditions
`staOut` | Thermodynamic state at compressor's out conditions
`TAmb` | Ambient temperature

Moreover, two approaches can be identified in general: A polynomial and a power approach. The characteristics of these approaches are presented below.

#### Polynomial approaches

A generic polynomial approach is presented below:
`ηeng = corFact * sum(a[i]*P[i]^b[i] for i in 1:nT)`
Actually, four polynomial approaches are implemented in this package.

#### Power approaches

A generic power approach is presented below:
`ηeng = corFact * a * product(P[i]^b[i] for i in 1:nT)`
Actually, one power approache is implemented in this package.

#### References

In the following, some general references are given for information about calculating efficiencies of compressors:

V. A. Cara Martin and R. Radermacher (2015): AHRI Project 8013: A Study of Methods to Represent Compressor Performance Data over an Operating Envelope Based on a Finite Set of Test Data. Publisher: Air-Conditioning, Heating, and Refrigeration Institute (AHRI)

## Contents

Name | Description
--- | ---
PartialEngineEfficiency | Based model used by all models describing engine efficiencies
PolynomialEngineEfficiency | Model describing engine efficiency based on polynomial approach
PowerEngineEfficiency | Model describing flow engine efficiency on power approach
SpecifiedEfficiencies | Package that engine efficiencies that are specifiied

## Revisions

- October 19, 2017, by Mirko Engelpracht:
  First implementation (see issue 467).

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