Concept

Impeller

Publications associées (32)

The influence of splitter blades and meridional profiles on the performance of small-scale turbopumps for ORC applications; analysis, neural network modeling and optimization

Jürg Alexander Schiffmann, Sajjad Zakeralhoseini

This work presents the influence of splitters on the performance of small-scale turbopumps for organic Rankine cycle applications numerically. Different design parameters, such as impeller diameter at the outlet, number of blades, blade angle at the traili ...

2023

Small-scale turbopumps for waste heat recovery applications based on an organic Rankine cycle: a study from pre-design to experimental validation

Sajjad Zakeralhoseini

The organic Rankine cycle (ORC) system is among the technologies applied to exploit waste heat in vehicles. Since common organic fluids have lower latent heat than water, higher mass flow rates are required to convert the same waste heat, considerably incr ...

EPFL2023

The effects of the tip clearance on the performance of small-scale turbopumps for ORC applications; analysis and modeling

Jürg Alexander Schiffmann, Sajjad Zakeralhoseini

In this paper, the influence of tip clearance on the performance of small-scale turbopumps is studied numerically on extensive parameter ranges suitable for organic Rankine cycle applications. A novel and fully parameterized design model is developed and u ...

Technical University of Munich2021

A reduced order model to predict the machining time and cost of small-scale radial-inflow turbines

Jürg Alexander Schiffmann, Matthias Geiselhart

This paper proposes a novel approach to predict the machining time of small-scale radial-inflow turbine impellers for organic Rankine cycle power systems based on preliminary design parameters. The time prediction method uses machining databases of differe ...

Technical University of Munich2021

Scale limitations of gas bearing supported turbocompressors for vapor compression cycles

Jürg Alexander Schiffmann

An analysis of single-stage centrifugal compressors supported on dynamic, gas lubricated bearings for driving vapor compression cycles suggests that the maximum feasible compressor power is limited, primarily by the bearing load capacity, in the range from ...

2020

Unsteady Flow Numerical Simulations on Internal Energy Dissipation for a Low-Head Centrifugal Pump at Part-Load Operating Conditions

François Avellan, Xiaoran Zhao

Dredge pumps are usually operated at part-load conditions, in which the low-solidity centrifugal impeller could experience large internal energy dissipation, related to flow separation and vortices. In this study, SST k- and SAS-SST turbulence models were ...

2019

Oxygen diffusion through air–water free surfaces in a pump–turbine operating in condenser mode

François Avellan, Elena Vagnoni, Loïc Andolfatto, Pierre Leroy

The present research aims at understanding the mass transfer of air into water in a reversible pump turbine operating in condenser mode. In particular, the diffusion of oxygen through the water free-surface both in the vaneless gap between the impeller bla ...

2019

Mitigation of tip leakage induced phenomena in a low Reynolds number centrifugal compressor via blade loading distribution

Markus Diehl

Reduced-scale refrigeration compressors supported on gas-lubricated bearings have been identified as a key technology for domestic heat pump applications, in order to improve both the system efficiency and the reliability. Unfortunately, reduced-scale mach ...

EPFL2019

Impact of large tip clearance ratios on the performance of a centrifugal compressor

Jürg Alexander Schiffmann, Markus Diehl

Ultra-compact and fast spinning turbomachinery is a key technology to increase performance of domestic heating applications and to address decentralization of power and heat as a consequence of the rise of renewable energy sources. Recently, a heat pump us ...

2019

Interaction of a rotating two-phase flow with the pressure and torque stability of a reversible pump-turbine operating in condenser mode.

François Avellan, Elena Vagnoni, Loïc Andolfatto, Pierre Leroy

The operation of a reversible pump-turbine in condenser mode requires to dewater the impeller by closing the guide vanes and injecting compressed air in the draft tube cone to reduce the friction torque on the impeller blades. A water discharge is injected ...

2018

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