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Retrofittable Solutions Capability for Gas Turbine Compressors^{ †}

^{1}

^{2}

^{*}

^{†}

## Abstract

**:**

## 1. Introduction

## 2. Computational Framework

#### 2.1. Domain Discretization

#### 2.2. Boundary Conditions

#### 2.3. Mass Extraction Treatment

## 3. Results

^{®}Xeon

^{®}CPU E5-2680 v2 @$2.80$ GHz, to reach the steady state convergence. The RMS residual experiences a drop of four decades in about 5000 multi-grid cycles on two grid levels. For all the calculated operating points, the solution convergence was obtained with approximately the same number of iterations showing a good robustness even in presence of separated flow regions inside the computational domain.

#### 3.1. Comparison with Measurements

#### 3.2. Minimum Environmental Load Reduction Strategies

## 4. Conclusions

## Author Contributions

## Funding

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## Abbreviations

BO | Blow-off |

IGV | Inlet guide vane |

IX | IGV extra-closure |

MEL | Minimum environmental load |

OGV | Outlet guide vane |

RES | Renewable energy systems |

TET | Total exit temperature |

Nomenclature | |

$AVDR$ | Axial velocity by density ratio, $AVDR=\frac{{\left(\rho {c}_{x}\right)}_{out}}{{\left(\rho {c}_{x}\right)}_{in}}$ |

c | Absolute velocity |

C | Blade chord |

$DF$ | Diffusion factor (Lieblein), $DF=1-\frac{{w}_{out}}{{w}_{in}}+\frac{\Delta \left(r{w}_{\theta}\right)}{2{\sigma}_{m}{r}_{m}{w}_{in}}$ |

$FF$ | Inlet flow function, $FF=\frac{\dot{m}\sqrt{{T}_{0}}}{{p}_{0}}$ |

h | Specific enthalpy |

$\dot{m}$ | Mass flow rate |

N | Number of blades |

p | Pressure |

r | Radius |

s | Blade row tangential spacing |

u | Peripheral velocity, $u=\mathrm{\Omega}r$ |

T | Absolute temperature |

x | Axial coordinate |

w | Relative velocity |

W | Compressor power input |

$\beta $ | Pressure ratio |

$\eta $ | Isentropic efficiency |

$\varphi $ | Flow coefficient, $\varphi =\frac{{c}_{x}}{u}$ |

$\psi $ | Load coefficient, $\psi =\frac{\Delta {h}_{0}}{{u}^{2}}$ |

$\sigma $ | Blade row mean solidity, $\sigma =\frac{{C}_{m}}{{s}_{m}}$ |

Subscripts | |

0 | Total quantity |

in | Inlet |

m | Mean |

out | Outlet |

ref | Reference |

tt | Total-to-total |

x | Axial |

$\rho $ | Density |

$\theta $ | Tangential |

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**Figure 1.**Generic daily power mix using programmable and renewable energy systems [2].

**Figure 2.**View of the rotor tip gap grid block (

**a**) and mass flow rate distribution for the compressor, with and without the meshed tip rotor (

**b**) (the axial position of the exit bleeds (EB) is indicated).

**Figure 4.**Compressor pressure at casing for the operating points experimentally tested: (

**a**) T23 (MEL), (

**b**) T24, (

**c**) T26.

**Figure 7.**Diffusion factor comparison between analyzed MEL configurations (

**a**) and part-load standard MEL operating condition (

**b**).

**Figure 10.**View of stages 10 to 15 + OGV; recirculating flow regions are highlighted by iso-surface of zero axial velocity (flow goes from right to left).

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## Share and Cite

**MDPI and ACS Style**

Ricci, M.; Mosele, S.G.; Benvenuto, M.; Astrua, P.; Pacciani, R.; Marconcini, M.
Retrofittable Solutions Capability for Gas Turbine Compressors. *Int. J. Turbomach. Propuls. Power* **2022**, *7*, 3.
https://doi.org/10.3390/ijtpp7010003

**AMA Style**

Ricci M, Mosele SG, Benvenuto M, Astrua P, Pacciani R, Marconcini M.
Retrofittable Solutions Capability for Gas Turbine Compressors. *International Journal of Turbomachinery, Propulsion and Power*. 2022; 7(1):3.
https://doi.org/10.3390/ijtpp7010003

**Chicago/Turabian Style**

Ricci, Martina, Stefano Gino Mosele, Marcello Benvenuto, Pio Astrua, Roberto Pacciani, and Michele Marconcini.
2022. "Retrofittable Solutions Capability for Gas Turbine Compressors" *International Journal of Turbomachinery, Propulsion and Power* 7, no. 1: 3.
https://doi.org/10.3390/ijtpp7010003