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KATHY JOHNSON

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KATHY JOHNSON

Professor of Mechanical and Aerospace Engineering


GT2022-82180 Experimental investigation into oil film thickness and behaviour near an aero-engine bearing (2022)
Conference Proceeding
Sinha, A., Hann, D., Johnson, K., & Walsh, M. (2022). GT2022-82180 Experimental investigation into oil film thickness and behaviour near an aero-engine bearing. In Proceedings of the ASME TURBO EXPO 2022: Turbomachinery Technical Conference & Exposition. GT 2022 June 13-17, 2022, Rotterdam, Netherlands. https://doi.org/10.1115/GT2022-82180

In an aero-engine transmission system, bearings are used for shaft location and load support. These bearings are housed in bearing chambers and oil is supplied to the chamber for lubrication and cooling. To achieve the targets of ACARE Flightpath 205... Read More about GT2022-82180 Experimental investigation into oil film thickness and behaviour near an aero-engine bearing.

COUPLED EULERIAN THIN FILM MODEL AND LAGRANGIAN DISCRETE PHASE MODEL TO PREDICT FILM THICKNESS INSIDE AN AERO-ENGINE BEARING CHAMBER (2022)
Conference Proceeding
Mouvanal, S., Singh, K., Jefferson-Loveday, R., Ambrose, S., Eastwick, C., Johnson, K., & Jacobs, A. (2022). COUPLED EULERIAN THIN FILM MODEL AND LAGRANGIAN DISCRETE PHASE MODEL TO PREDICT FILM THICKNESS INSIDE AN AERO-ENGINE BEARING CHAMBER. In Proceedings of Global Power and Propulsion Society. https://doi.org/10.33737/gpps22-tc-68

In aero-engine bearing chambers, two-phase shearing flows are difficult to predict as Computational Fluid Dynamics (CFD) RANS models tend to overestimate interfacial turbulence levels, leading to inaccuracies in the modelling of the flow. Turbulence... Read More about COUPLED EULERIAN THIN FILM MODEL AND LAGRANGIAN DISCRETE PHASE MODEL TO PREDICT FILM THICKNESS INSIDE AN AERO-ENGINE BEARING CHAMBER.

How Do Interfacial Shear and Gravity Affect the Oil Film Characteristics Near an Aero-Engine Bearing? (2022)
Journal Article
Sinha, A., Brewster, B., Johnson, K., Walsh, M., & Hann, D. (2022). How Do Interfacial Shear and Gravity Affect the Oil Film Characteristics Near an Aero-Engine Bearing?. Journal of Engineering for Gas Turbines and Power, 144(10), Article 101001. https://doi.org/10.1115/1.4055211

Recent demand for reducing carbon emission and for increasing engine efficiency has led aero-engine manufacturers to strive for a better oil flow system. Aero-engine bearing chambers that house the shaft-support bearings are among the most challengin... Read More about How Do Interfacial Shear and Gravity Affect the Oil Film Characteristics Near an Aero-Engine Bearing?.

Experimental Investigation Into Oil Shedding From a Rotating Cup Geometry (2022)
Conference Proceeding
Cageao, P. P., Johnson, K., Ambrose, S., & Omar, R. (2022). Experimental Investigation Into Oil Shedding From a Rotating Cup Geometry. In Proceedings of the ASME 2022 Turbomachinery Technical Conference & Exposition Turbo Expo 2022 June 13-17, 2022, Rotterdam, The Netherlands. https://doi.org/10.1115/GT2022-82195

Oil shedding from rotating components and static elements within rotating systems has a number of applications within the design and understanding of transmission systems as well as wider industrial applications. There is a reasonable body of prior r... Read More about Experimental Investigation Into Oil Shedding From a Rotating Cup Geometry.

Numerical Investigation Into Maximum Pressure Capability of Intershaft Hydraulic Seals (2022)
Conference Proceeding
Warusevitane, A., Johnson, K., & Ambrose, S. (2022). Numerical Investigation Into Maximum Pressure Capability of Intershaft Hydraulic Seals. In Proceedings of ASME Turbo Expo 2022 Turbomachinery Technical Conference and Exposition GT2022 June 13-17, 2022, Rotterdam, The Netherlands. https://doi.org/10.1115/GT2022-82196

Hydraulic seals are used as intershaft seals in aero-engines and consist of an oil filled trough on the higher speed shaft and a fin on the lower speed shaft that dips into the oil forming the seal. Rotation is imparted to the sealing fluid within th... Read More about Numerical Investigation Into Maximum Pressure Capability of Intershaft Hydraulic Seals.

Investigation of Droplet Shedding in an Aeroengine Bearing Chamber Using Convolutional Neural Networks (2022)
Conference Proceeding
Farbrother, K., Cageao, P. P., Johnson, K., & Ambrose, S. (2022). Investigation of Droplet Shedding in an Aeroengine Bearing Chamber Using Convolutional Neural Networks. In Proceedings of the ASME 2022 Turbomachinery Technical Conference & Exposition GT2022 June 13-17, 2022, Rotterdam, The Netherlands. https://doi.org/10.1115/GT2022-82275

More efficient aeroengines are needed to reduce the environmental impact of civil aviation. Design changes for increased efficiency mean that higher loads are transmitted through the bearings supporting the rotating shafts. Better bearing chamber des... Read More about Investigation of Droplet Shedding in an Aeroengine Bearing Chamber Using Convolutional Neural Networks.

Droplet Impact on a Curved Moving Liquid Film (2022)
Conference Proceeding
Sinha, A., Ramakrishnan, V., & Johnson, K. (2022). Droplet Impact on a Curved Moving Liquid Film. In Proceedings of the ASME TURBO EXPO 2022: Turbomachinery Technical Conference & Exposition. GT 2022 June 13-17, 2022, Rotterdam, Netherlands. https://doi.org/10.1115/GT2022-79505

The European Commission has set targets to reduce the emissions of CO2 and NOx by 75% and 90% respectively, per passenger kilometre, by 2050. Computational modelling of elements within the aero-engine will play a key role in achieving this goal. Curr... Read More about Droplet Impact on a Curved Moving Liquid Film.

How do the liquid properties affect the entrapment of bubbles in gas sheared liquid flows? (2021)
Journal Article
Sinha, A., Cherdantsev, A., Johnson, K., Vasques, J., & Hann, D. (2021). How do the liquid properties affect the entrapment of bubbles in gas sheared liquid flows?. International Journal of Heat and Fluid Flow, 92, Article 108878. https://doi.org/10.1016/j.ijheatfluidflow.2021.108878

A large number of industries use fossil fuels for the purpose of cooling and lubrication utilizing a gas stream that acts as a shearing force on the liquid surface. Decreasing the carbon footprint of these processes needs an improved understanding of... Read More about How do the liquid properties affect the entrapment of bubbles in gas sheared liquid flows?.

Simulation of a Simplified Aeroengine Bearing Chamber Using a Fully Coupled Two-Way Eulerian Thin Film/Discrete Phase Approach Part II: Droplet Behavior in the Chamber (2021)
Journal Article
Nicoli, A., Johnson, K., & Jefferson-Loveday, R. (2021). Simulation of a Simplified Aeroengine Bearing Chamber Using a Fully Coupled Two-Way Eulerian Thin Film/Discrete Phase Approach Part II: Droplet Behavior in the Chamber. Journal of Engineering for Gas Turbines and Power, 143(10), 1-13. https://doi.org/10.1115/1.4051561

Within aeroengines, bearing chambers exhibit a highly complex two-phase environment as a result of the complex air/oil interactions. The desire to operate at both higher temperatures and shaft speeds requires a sufficient understanding of these syste... Read More about Simulation of a Simplified Aeroengine Bearing Chamber Using a Fully Coupled Two-Way Eulerian Thin Film/Discrete Phase Approach Part II: Droplet Behavior in the Chamber.

Simulation of a Simplified Aeroengine Bearing Chamber Using a Fully Coupled Two-Way Eulerian Thin Film/Discrete Phase Approach Part I: Film Behavior Near the Bearing (2021)
Journal Article
Nicoli, A., Johnson, K., & Jefferson-Loveday, R. (2021). Simulation of a Simplified Aeroengine Bearing Chamber Using a Fully Coupled Two-Way Eulerian Thin Film/Discrete Phase Approach Part I: Film Behavior Near the Bearing. Journal of Engineering for Gas Turbines and Power, 143(10), 1-12. https://doi.org/10.1115/1.4051560

Previous work at the Gas Turbine and Transmissions Research Center (G2TRC) has highlighted the need for an adequate computational model, which can appropriately model the oil shedding behavior from bearings. Oil can break up forming droplets and liga... Read More about Simulation of a Simplified Aeroengine Bearing Chamber Using a Fully Coupled Two-Way Eulerian Thin Film/Discrete Phase Approach Part I: Film Behavior Near the Bearing.