Browsing by Author "Wang, Lu"

Now showing 1 - 3 of 3
  • Thumbnail Image
    ItemOpen Access
    Development and application of a preliminary design methodology for modern low emissions aero combustors
    (SAGE, 2020-04-23) Liu, Yize; Sun, Xiaoxiao; Sethi, Vishal; Li, Yi-Guang; Nalianda, Devaiah; Abbott, David; Gauthier, Pierre Q.; Xiao, Bairong; Wang, Lu
    In this article, a preliminary design framework containing a detailed design methodology is developed for modern low emissions aero combustors. The inter-related design elements involving flow distribution, combustor sizing, heat transfer and cooling, emission and performance are coupled in the design process. The physics-based and numerical methods are provided in detail, in addition to empirical or semi-empirical methods. Feasibility assessment on the developed work is presented via case studies. The proposed combustor sizing methodology produces feasible combustor dimensions against the public-domain low emissions combustors. The results produced by the physics-based method show a reasonable agreement with experimental data to represent NOx emissions at key engine power conditions. The developed emission prediction method shows the potential to assess current and future technologies. A two-dimensional global prediction on liner wall temperature distribution for different cooling systems is reasonably captured by the developed finite difference method. It can be of use in the rapid identification of design solutions and initiating the optimisation of the design variables. The altitude relight efficiency predicted shows that the method could be used to provide an indicative assessment of combustor altitude relight capability at the preliminary design phase. The methodology is applied and shows that it enables the automatic design process for the development of a conceptual lean staged low emissions combustor. The design evaluation is then performed. A sensitivity analysis is carried out to assess the design uncertainties. The optimisation of the air distribution and cooling geometrical parameters addresses the trade-off between the NOx emissions and liner wall cooling, which demonstrates that the developed work has potential to identify and solve the design challenges at the early stages of the design process.
  • Thumbnail Image
    ItemOpen Access
    Navigating the blurred work-life boundary under the hybrid working context: how the appraisal of emotions prompts individual boundary management tactics
    (British Academy of Management, 2023-09-06) Xu, Mengyi; Wang, Lu
    Hybrid working heightens work-life boundaries blurring. This can create the need for employees to constantly navigate evolving demands in their work-nonwork environment, often before formalized strategic, organisational, and managerial interventions are developed and/or implemented. Therefore, understanding why and how adapt to boundary blurs and manage their work-life balance is critical for effective hybrid working. Drawn on appraisal theories of emotion, we argue that employees' appraisals of boundary-blurring situations can elicit emotions, which prompt employees to navigate and adapt to their blurred boundaries in their work-life balance. We substantiate this with a longitudinal one-month dairy and post-interview study using a sample of 34 employees in the UK Higher Education (HE) sector, where hybrid working has been widely applied. Our finding unveils that both positive and negative emotions help the individual efficiently respond to boundary blurring, using prevention- and promotion-oriented tactics; the former associated with negative emotions focuses on the temporary work-life blurring, whereas the latter associated with positive emotions that attempts to leverage resources and opportunities for long term work-life balance. The findings make practical implications for employees and organisations on how to effectively manage hybrid working by understanding work-life boundaries.
  • Thumbnail Image
    ItemOpen Access
    Review of modern low emissions combustion technologies for aero gas turbine engines
    (Elsevier, 2017-09-12) Liu, Yize; Sun, Xiaoxiao; Sethi, Vishal; Nalianda, Devaiah; Li, Yi-Guang; Wang, Lu
    Pollutant emissions from aircraft in the vicinity of airports and at altitude are of great public concern due to their impact on environment and human health. The legislations aimed at limiting aircraft emissions have become more stringent over the past few decades. This has resulted in an urgent need to develop low emissions combustors in order to meet legislative requirements and reduce the impact of civil aviation on the environment. This article provides a comprehensive review of low emissions combustion technologies for modern aero gas turbines. The review considers current high Technologies Readiness Level (TRL) technologies including Rich-Burn Quick-quench Lean-burn (RQL), Double Annular Combustor (DAC), Twin Annular Premixing Swirler combustors (TAPS), Lean Direct Injection (LDI). It further reviews some of the advanced technologies at lower TRL. These include NASA multi-point LDI, Lean Premixed Prevaporised (LPP), Axially Staged Combustors (ASC) and Variable Geometry Combustors (VGC). The focus of the review is placed on working principles, a review of the key technologies (includes the key technology features, methods of realising the technology, associated technology advantages and design challenges, progress in development), technology application and emissions mitigation potential. The article concludes the technology review by providing a technology evaluation matrix based on a number of combustion performance criteria including altitude relight auto-ignition flashback, combustion stability, combustion efficiency, pressure loss, size and weight, liner life and exit temperature distribution.