Johan Steimes

Study of a Two-Phase Flow Pump and Separator System

The Aero-Thermo-Mechanics (ATM) Department of ULB (Universit Libre de Bruxelles) is developing an original system to pump and separate a two-phase flow. Many applications need to extract a certain phase of a multiphase flow: oil extraction, flow in nuclear pumps, flow in aircraft lubrication systems, pulp and paper processing, etc. The main objective of this study is to obtain a lightweight, compact, and efficient system that can both extract the gas of a two-phase flow and increase the pressure of the liquid phase. Prototypes with different designs were first tested at ULB on a specific test bench using water and air. The current prototype is a kind of axial-centrifugal pump. The axial part is used to separate the two phases of the flow and to collect, in the centrifugal part, the liquid phase only. The test results of the water-air prototypes have allowed to identify the key design and working parameters for efficient separation and pumping. A theoretical model has also been developed to describe the behavior of these prototypes. After successful tests with water-air mixtures, the technology has been implemented for a hot oil-air mixture. The tests with oil-air mixtures are performed on the aeroengine lubrication system test bench that the ATM Department developed and continues developing for other projects. At the same time, the flow field in the pump and separator system is being studied with commercial computational fluid dynamics software packages. Several two-phase flow models are considered for this particular application.

Study of an Air-Oil Pump and Separator Solution for Aero Engine Lubrication Systems

Lubrication system of aero engines have to manage a two-phase flow of oil and air created in air-sealed bearing chambers. A part of this flow goes through scavenge pumps and a de-aerator before returning to the tank, the other part passes through a de-oiler before leaving the engine. The Aero-Thermo-Mechanics Department of Universite Libre de Bruxelles is developing an original and integrated system to pump and separate a liquid-gas flow. This system helps to reduce the complexity and the oil consumption of aero-engine lubrication systems by replacing the de-oiler, the de-aerator and scavenge pumps. The prototype is composed of an axial part (blades and metallic foam) that performs the separation and a radial part that pressurize the liquid. De-oiling efficiency is measured with a radio-tracer measurement system. This paper presents the test results of four configurations (different radii, flow paths, size of the metallic foam). Droplet size measurements at the inlet and the outlet of the prototype are also presented. A physical interpretation has been developed and is presented.Copyright

Performance Study of an Air-Oil Pump and Separator Solution

Many applications need to extract a certain phase from a multiphase flow like in oil extraction, flow in nuclear power plants, aircraft lubrication systems, etc. The Aero-Thermo-Mechanics (ATM) Department of Universitee Libre de Bruxelles (ULB) is developing an original system to extract the gas from a liquid-gas flow together with increasing the pressure of the liquid phase. This system will help to reduce the complexity and the oil consumption of aeroengine lubrication systems.This paper will summarise the results of a first air/oil prototype. It will also present the guidelines learned from this prototype and used to design a second version of the integrated pump and separator. A newly developed oil consumption measurement system will also be presented. Based on previous results, on litterature review and on an in-house theoretical model, the paper will explain theoretically how the separation efficiency is affected by the particle distribution at the inlet of the prototype, and by the key parameters identified in different studies. Finally the conclusions will present the lessons learned through the design and tests of these two prototypes and the future work will be presented.Copyright

Set-up of a pump as turbine use in micro-pumped hydro energy storage: a case of study in Froyennes Belgium

Its maturity makes pumped hydro energy storage (PHES) the most used technology in energy storage. Micro-hydro plants (<100 kW) are globally emerging due to further increases in the share of renewable electricity production such as wind and solar power. This paper presents the design of a micro-PHES developed in Froyennes, Belgium, using a pump as turbine (PaT) coupled with a variable frequency driver (VFD). The methods adopted for the selection of the most suitable pump for pumping and reverse mode are compared and discussed. Controlling and monitoring the PaT performances represent a compulsory design phase in the analysis feasibility of PaT coupled with VFD in micro PHES plant. This study aims at answering technical research aspects of µ-PHES site used with reversible pumps.

Investigation on an Oil Aeration Measurement Technique for the Study of Pump Performance in an Aircraft Engine Lubrication System

Previous studies on feed pump performance conducted on the ULB-ATM lubrication system test bench showed the dependence of cavitation and volumetric efficiency with inlet pressure, rotational speed and aeration. This paper presents a technique of aeration measurement applied on the test bench. After a description of the device and a theoretical review of the aeration, the paper shows that the method has been tested with success. The paper illustrates it with a series of tests showing the level of aeration obtained in different operating conditions and a comparison with a pump characteristic measured on the bench.Copyright