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Centrifuges

Centrifuges with hydraulic drive

[A sketch of a centrifgure with hydraulic drive] [A photograph of a centrifgure with hydraulic drive]

Fig. A sketch and a photograph of a centrifgure with hydraulic drive.

Centrifuges are used for separating solid particles from the fluid of different density, for example for cleaning oil in car engines. High rotation speed of the rotor creates large centrifugal forces, pulling heavier particles to the side of the rotor, where they stay until removed during a regular maintenance, or from where they are removed continuously by a special mechanism. Frequently, the rotor of the centrifuge is driven by a separate electric motor, or by a shaft from the car engine. A sketch of a centrifuge with a hydraulic drive is shown in Figure. In such a centrifuge the fluid is pumped into the rotor and exits through the nozzles. The nozzle thrust creates torque driving the centrifuge, thus eliminating the need for a separate motor. Notice the nozzles on the photograph of the centrifuge.

A centrifuge with hydraulic drive is an interesting object from the fluid dynamics point of view. To achieve high efficiency, the hydraulic resistance of the inner, quickly rotating with the rotor, passages should be minimised. At the same time the fluid should pass through an area far away from the axis of rotation, where the centrifugal force is greater. Nozzle efficiency is crucial. The air in the gap between the rotor and the centrifuge cover also moves, and the air friction makes a significant contribution. Jets from the nozzles might break down into a fine spray and hit the rotor, slowing it down. Optimizing such a device is quite a challenging task, but this can, indeed, be done.

Try it, it is easy and !

Timeline:

  • Will be in Lille 11-12 December 2025. On 12th, will give a talk at (Note the non-standard time, 2pm!).

  • Attended and gave a plenary talk at , Aligarh (U.P), India, 20-23 December 2024.

  • Attended the at the , Germany 28 July - 2 August 2024.

  • Gave a talk on at the .

  • Gave a talk on Bounding time averages: a road to solving the problem of turbulence at Institut de Mathématiques de Bordeaux, Bordeaux, May 4, 2023.

  • Gave a talk on at Institut Pprime, Bordeaux on May 3, 2023.

  • Talk at Department of Engineering, University of Cambridge, 4 November 2022, as part of the CUED Fluids seminar series, video: Joint work with Owen Tutty and Hanying Yang.

  • On August 15, 2022, gave (online) an invited talk "On the path to solving the problem of turbulence" at the

  • On July 22, 2022, gave (online) a talk "Bounds for time averages: towards solving the problem of turbulence" at the

  • In January-April 2022 was a long-term participant of the . Gave two talks: and .

  • Gave a talk Auxiliary functionals: a path to solving the problem of turbulence at on March 4, 2021. Links to and .

  • Gave a talk on at IPAM, Wednesday, January 13, 2021, as part of the workshop on Transport and Mixing in Complex and Turbulent Flows. Great talks, all recorded, highly recommended.

  • Gave a talk Accelerating time averaging at 73rd Annual Meeting of the APS Division of Fluid Dynamics, November 22, 2020: and video.

  • 2020: the virus ... living online ... most of the year working on additional administration and teaching related to the pandemic ...

  • Gave a talk at , Snowbird, Utah, U.S, May 19 - 23, 2019.

  • Gave a keynote lecture at the workshop , The Fields Institute, Toronto, April 15-18, 2019.

  • Gave a talk at 26-29 March 2019, Haus der Kirche, Bad Herrenalb, Germany.

  • Gave a seminar talk on Accelerating time averaging using auxiliary functions at the Aerodynamics and Flight Mechanics group seminar, University of Southampton, on 6 February 2019

  • Visited the in September 13-30, 2018.

  • Attended , London, August 29-31, 2018, with a talk Large-scale motions for the QSQH theory (with Chi Zhang).

  • Gave a talk on Questions concerning quasi-steady mechanism of the Reynolds number, pressure gradient, and geometry effect on drag reduction at the Aachen, Germany, 15-16 March 2018.

  • Gave a lecture course , with Giovanni Fantuzzi providing exercise sessions, at

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    Sergei Chernyshenko