Professor KATHY JOHNSON's Outputs (36)

Characterising Horizontal Two-Phase Flows Using Structured-Planar Laser-Induced Fluorescence (S-PLIF) Coupled With Simultaneous Two-Phase PIV (S2P-PIV) (2024)
Presentation / Conference Contribution
Sherif, A. A., Hann, D. B., & Johnson, K. (2024, July). Characterising Horizontal Two-Phase Flows Using Structured-Planar Laser-Induced Fluorescence (S-PLIF) Coupled With Simultaneous Two-Phase PIV (S2P-PIV). Presented at 21st International Symposium on Applications of Laser and Imaging Techniques to Fluid Mechanics, Lisbon, Portugal

Understanding the physics that underpins the behaviors of two-phase flows is immensely useful for a diverse number of industries, including oil and gas, nuclear, and aerospace. Stratified air-liquid two-phase flows are amenable to the application of two... Read More about Characterising Horizontal Two-Phase Flows Using Structured-Planar Laser-Induced Fluorescence (S-PLIF) Coupled With Simultaneous Two-Phase PIV (S2P-PIV).

Comparative Analysis Of Brightness-Based Laser-Induced Fluorescence (BBLIF) And Structured Planar Laser-Induced Fluorescence (S-PLIF) For Film Thickness Measurement In Two-Phase Flow (2024)
Presentation / Conference Contribution
Sherif, A. A., Johnson, K., & Hann, D. (2024, July). Comparative Analysis Of Brightness-Based Laser-Induced Fluorescence (BBLIF) And Structured Planar Laser-Induced Fluorescence (S-PLIF) For Film Thickness Measurement In Two-Phase Flow. Presented at 21st International Symposium on Applications of Laser and Imaging Techniques to Fluid Mechanics, Lisbon Portugal

Improved understanding of the interactions between gas and liquid phases in gas sheared film flow is crucial for n improved capability to employ computational modelling in the future to optimize systems, thereby reducing environmental impact, increas... Read More about Comparative Analysis Of Brightness-Based Laser-Induced Fluorescence (BBLIF) And Structured Planar Laser-Induced Fluorescence (S-PLIF) For Film Thickness Measurement In Two-Phase Flow.

GT2022-82180 Experimental investigation into oil film thickness and behaviour near an aero-engine bearing (2022)
Presentation / Conference Contribution
Sinha, A., Hann, D., Johnson, K., & Walsh, M. (2022, June). GT2022-82180 Experimental investigation into oil film thickness and behaviour near an aero-engine bearing. Presented at ASME Turbo Expo 2022, Rotterdam, Netherlands

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)
Presentation / Conference Contribution
Mouvanal, S., Singh, K., Jefferson-Loveday, R., Ambrose, S., Eastwick, C., Johnson, K., & Jacobs, A. (2022, September). COUPLED EULERIAN THIN FILM MODEL AND LAGRANGIAN DISCRETE PHASE MODEL TO PREDICT FILM THICKNESS INSIDE AN AERO-ENGINE BEARING CHAMBER. Presented at GPPS Chania22, Chania, Greece

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)
Presentation / Conference Contribution
Cageao, P. P., Johnson, K., Ambrose, S., & Omar, R. (2022, June). Experimental Investigation Into Oil Shedding From a Rotating Cup Geometry. Presented at ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition, Rotterdam, Netherlands

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.

Experimental Investigation Into Oil Film Thickness and Behaviour Near an Aero-Engine Bearing (2022)
Presentation / Conference Contribution
Sinha, A., Hann, D., Johnson, K., & Walsh, M. (2022, June). Experimental Investigation Into Oil Film Thickness and Behaviour Near an Aero-Engine Bearing. Presented at ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition, Rotterdam, Netherlands

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 Flight-path 20... Read More about Experimental Investigation Into Oil Film Thickness and Behaviour Near an Aero-Engine Bearing.

Investigation of Droplet Shedding in an Aeroengine Bearing Chamber Using Convolutional Neural Networks (2022)
Presentation / Conference Contribution
Farbrother, K., Cageao, P. P., Johnson, K., & Ambrose, S. (2022, June). Investigation of Droplet Shedding in an Aeroengine Bearing Chamber Using Convolutional Neural Networks. Presented at ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition, Rotterdam, Netherlands

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.

Numerical Investigation Into Maximum Pressure Capability of Intershaft Hydraulic Seals (2022)
Presentation / Conference Contribution
Warusevitane, A., Johnson, K., & Ambrose, S. (2022, June). Numerical Investigation Into Maximum Pressure Capability of Intershaft Hydraulic Seals. Presented at ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition, Rotterdam, Netherlands

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.

Droplet Impact on a Curved Moving Liquid Film (2022)
Presentation / Conference Contribution
Sinha, A., Ramakrishnan, V., & Johnson, K. (2022, June). Droplet Impact on a Curved Moving Liquid Film. Presented at ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition, Rotterdam, Netherlands

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 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.

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.

Operating under jet splashing conditions can increase the capture efficiency of scoops (2019)
Journal Article
Kruisbrink, A., Paleo Cageao, P., Morvan, H., & Simmons, K. (2019). Operating under jet splashing conditions can increase the capture efficiency of scoops. International Journal of Heat and Fluid Flow, 76, 296-308. https://doi.org/10.1016/j.ijheatfluidflow.2018.11.010

Scoops are used in aero-engines to capture oil and direct the oil flow for the lubrication of bearings, where a direct oil injection is not effective or possible. The design of scoops focuses on the capture of oil to aim for the highest capture effic... Read More about Operating under jet splashing conditions can increase the capture efficiency of scoops.

Assessment of the Oil Scoop Capture Efficiency in High Speed Rotors (2018)
Journal Article
Paleo Cageao, P., Simmons, K., Prabhakar, A., & Chandra, B. (2019). Assessment of the Oil Scoop Capture Efficiency in High Speed Rotors. Journal of Engineering for Gas Turbines and Power, 141(1), Article 012401. https://doi.org/10.1115/1.4040812

Experimental research was conducted into a scooped rotor system that captures oil from a stationary jet and directs it through passages within the shaft to another axial location. Such a system has benefits for delivering oil via under-race feed to a... Read More about Assessment of the Oil Scoop Capture Efficiency in High Speed Rotors.

Experimental investigation into gas turbine oil scoop capture efficiency (2018)
Journal Article
Paleo Cageao, P., Simmons, K., Prabhakar, A., & Chandra, B. (2019). Experimental investigation into gas turbine oil scoop capture efficiency. Journal of Engineering for Gas Turbines and Power, 141(1), Article 012401. https://doi.org/10.1115/1.4040812

Experimental research was conducted into a scooped rotor system that captures oil from a stationary jet and directs it through passages within the shaft to another axial location. Such a system has benefits for delivering oil via under-race feed to a... Read More about Experimental investigation into gas turbine oil scoop capture efficiency.

Numerical investigations to assess the impact of shaft speed on the performance of scoop devices (2018)
Presentation / Conference Contribution
Prabhakar, A., Abdalla Abakr, Y., & Simmons, K. (2018, June). Numerical investigations to assess the impact of shaft speed on the performance of scoop devices. Presented at ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition, Oslo, Norway

The demand for continuous and efficient lubrication in aeroengine bearing assemblies has encouraged the development of scoop based lubrication systems. Using a scooped rotor in conjunction with axial passages within the shaft, a scoop system can prov... Read More about Numerical investigations to assess the impact of shaft speed on the performance of scoop devices.

Mechanisms for Residence Volume Reduction in Shallow Sump (2017)
Journal Article
Chandra, B., Simmons, K., & Murphy, A. (2018). Mechanisms for Residence Volume Reduction in Shallow Sump. Journal of Engineering for Gas Turbines and Power, 140(3), Article 032601. https://doi.org/10.1115/1.4037871

© 2018 by ASME. Gas turbine aero-engines employ fast rotating shafts that are supported by bearings at several axial locations along the engine. Due to extreme load and heat, oil is injected to the bearings to aid lubrication and cooling. The oil is... Read More about Mechanisms for Residence Volume Reduction in Shallow Sump.

A coupled Euler-Lagrange CFD modelling of droplets-to-film (2017)
Journal Article
Adeniyi, A. A., Morvan, H. P., & Simmons, K. A. (in press). A coupled Euler-Lagrange CFD modelling of droplets-to-film. Aeronautical Journal, 121(1246), https://doi.org/10.1017/aer.2017.107

In this paper, a droplet to film interaction model technique is presented. In the proposed approach, the liquid and gas continua are modelled using an enhanced Volume of Fluid (VoF) technique while the droplets are tracked using a Lagrangian framewor... Read More about A coupled Euler-Lagrange CFD modelling of droplets-to-film.

Experimental investigation of oil shedding from an aero-engine ball bearing at moderate speeds (2017)
Presentation / Conference Contribution
Santhosh, R., Hee, J. L., Simmons, K., Johnson, G., Hann, D., & Walsh, M. (2017, June). Experimental investigation of oil shedding from an aero-engine ball bearing at moderate speeds. Presented at ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition, Charlotte, North Carolina, USA

In civil aero-engine transmission system bearings are used for shaft location and load support. An experimental test facility in the University of Nottingham's Gas Turbine Transmissions Research Centre (G2TRC) was designed and commissioned to investi... Read More about Experimental investigation of oil shedding from an aero-engine ball bearing at moderate speeds.