Experimental and Numerical Study of Aerofoil with Leading Edge and Trailing Edge Serrations
Lead Research Organisation:
Brunel University London
Department Name: Mech. Engineering, Aerospace & Civil Eng
Abstract
The aim of this research is to develop a hybrid device that integrates the passive and active flow control mechanisms to work cooperatively and additively to reduce aerofoil noise and improve superior aerodynamic performances. The research aim will be in two parts: (A1). Develop and optimise the next generation aero-acoustic and aerodynamic devices through cooperative ability to enhance aerodynamic and aero-acoustic performance through assessment over a broad range of loading conditions and flow speeds. (A2). To integrate the hybrid devices into the structure of the aerofoil through researching advanced materials and manufacturing techniques required in the development stage.
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509437/1 | 01/10/2016 | 30/09/2021 | |||
| 1819059 | Studentship | EP/N509437/1 | 01/10/2016 | 30/06/2020 | Philip Woodhead |
| EP/R512990/1 | 01/10/2018 | 30/09/2023 | |||
| 1819059 | Studentship | EP/R512990/1 | 01/10/2016 | 30/06/2020 | Philip Woodhead |
| Description | My research has focused on passive flow control devices to reduce broadband noise through sawtooth, also called serration, trailing edge devices. I have investigated two key areas within this field of research: misalignment of serrated trailing edge and slit & double-rooted serrations. This study investigated experimental far-field noise measurements for variable flap angles to the serrated trailing edges to understand both the self-noise on the aerofoil and flow mechanisms. It investigated a combination of positive and negative serrated flap angles across the trailing edge. Five individual cases were studied. The effects of all misaligned trailing edges produced different noise characteristics to the conventional zero flap angle serrated trailing edge case. The misaligned trailing edge cases were more effective than serrated trailing edge at mid-to-high frequency and less effective than the low-to-mid frequency. A new parameter, the serration oscillation wavelength to form spanwise-wavy-serration cases, produced similar noise performances at low-to-mid frequency and outperformed at mid-to-high frequency in comparison to the conventional serrations. However, the spanwise-wavy-serration produced slight increases in high-frequency noise levels over the non-serrated baseline cases. The slit and double-rooted serrations research showcases experimental results for aerofoil trailing edge noise reduction targeting specific frequencies. This is achieved using destructive interference mechanisms, corresponding to the 180-degree phase-cancellation for acoustic radiation between the displaced roots of the slit and double-rooted serrations. Experimental results exhibited maximum noise reduction up to 8 dB due to phase-cancellation for both slit and double-rooted serrations, in comparison to the conventional serration. |
| Exploitation Route | The application of my research can be applied to aerospace, commercial fan industry and energy sector to reduce the overall noise emitted. It has benefits in reducing aerodynamic noise generated by the aerofoil for the wind turbine rotors, fan blades and commercial jet engine fan blades. The wind energy sector faces increasingly strict noise regulations and as a result, in order to meet these regulations, it reduces the rotation speed of their wind turbines. This can also be applied to commercial jet engines by reducing operation noise during takeoff and landing of aircraft. Finally, the commercial fans within ventilation systems require further work to reduces background noise. Further academic research is needed into different flow conditions, i.e. high flow speeds. |
| Sectors | Aerospace, Defence and Marine,Energy |
| Description | On the Double-Rooted-Serration and Slit Trailing Edge |
| Organisation | University of Southampton |
| Department | Institute of Sound and Vibration Research |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | I contributed to the investigation of double-rooted-serration and slit trailing edges. This involved investigating various combinations of geometrical parameters for noise measurements. This work is an ongoing project; further research will investigate the flow visuals to develop a greater understanding of the mechanisms. |
| Collaborator Contribution | He gave experience and guidance throughout the development of this research. This helped me to develop a new concept within this project. |
| Impact | New concept applied to the trailing edge through destructive interference mechanism that enables noise cancellation at specific frequencies. This work is still in progress. |
| Start Year | 2018 |
| Title | A METHOD FOR FORMING AN ADD-ON COMPONENT FOR AN AEROFOIL |
| Description | A method is provided for forming an add-on component for an aerofoil which enable the structure of the aerofoil to be tuned in order to reduce the amplitude of sound produced at frequency f peak when air flows in a flow direction from the leading edge over the trailing edge of an aerofoil. The method applies both to add-on components having a slitted formation and a Double-Rooted Trailing Edge Serration (abbreviated to "DRooTES"). |
| IP Reference | WO2020229829 |
| Protection | Patent granted |
| Year Protection Granted | 2020 |
| Licensed | No |
| Impact | The development has led to further funding with EPSRC IAA (Impact Acceleration Account) and research is ongoing. |