Trailing Edge Serration & Leading Edge Undulation Aero-acoustic Noise Reduction Mechanisms Through 3-Dimensional Flow Structure Analysis
Lead Research Organisation:
Brunel University London
Department Name: Mech. Engineering, Aerospace & Civil Eng
Abstract
The research will focus on three main stages. Stage 1 (approximately 10 months) will focus on the optimisation of aeroacoustic and aerodynamic performances of curved leading edge serrations that were inspired by those found on owl's wing (see Fig. 2). This new concept, which has never been attempted elsewhere before, was initiated in my final year Bachelor's project and the results so far have demonstrated that the serrations can in fact be carefully optimised to achieve simultaneous and significant improvements in aerofoil leading edge noise reductions (Fig. 3) and increased performance in lift generation (Fig. 4). Currently we are preparing to apply for a patent, to be supported by the RSDO, for this owl-inspired leading edge serration technology developed in my undergraduate dissertation project. My PhD proposal is to undertake more in-depth research to determine the fundamental mechanisms and seek to develop control strategies based on the same physical principles on the leading edge serration.
Organisations
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509437/1 | 01/10/2016 | 30/09/2021 | |||
| 1818453 | Studentship | EP/N509437/1 | 01/10/2016 | 30/06/2020 | Auris Juknevicius |
| EP/R512990/1 | 01/10/2018 | 30/09/2023 | |||
| 1818453 | Studentship | EP/R512990/1 | 01/10/2016 | 30/06/2020 | Auris Juknevicius |
| Description | 1. A novel experimental technique has been developed, that can be used to study a variety of low-speed airflows that are in contact with solid surfaces, an aerofoil in this particular case. This technique allows us to recreate the flow structure and this is done using extensive computer-processed experimental data. The technique also provides a novel appoach to study the flow generated noise in the time-frequency domain. This allows the researcher to extact more information to what is currently accepted as common practice in related research studies and can potentially open up possibilities for new research outcomes. 2. It has been demonstrated that aerofoil shape modification through trailing edge serrations can significantly alter the airflow in its close vicinity. This is accompanied by a change in noise signature that the passing flow produces when compared to the baseline aerofoil with an unmodified trailing edge. 3. Preliminary results have shown that using the newly developed experimental technique, noise produced through the interaction between the laminar flow and the aerofoil can be altered significantly, opening up a pathway to study laminar instability tonal noise. |
| Exploitation Route | The briefly described experimental technique has been applied to study the mechamism by which aerofoil trailing edge modification in the shape of serrations is able to reduce aerofoil noise. Although this research study has used this technique solely for this purpose, it could be adopted in a variety of studies that deal with turbulent flow-solid surface interactions. Most importantly, the new physical mechanisms studied in this project will open up new research avenues for the reduction of aerofoil self-noise. |
| Sectors | Aerospace, Defence and Marine |
| Title | Method for the temporal-spatial analysis of flow hydrodynamic interaction with an aerofoil trailing edge and its resulting noise |
| Description | The method employs an experimental technique that allows mimicking flow conditions, normally associated with the aerofoil trailing edge - turbulent boundary layer interaction broadband noise. This type of aerofoil self noise is generated, as the name implies, through the interaction between the aerofoil trailing edge and the turbulent boundary layer that develops over the aerofoil. The interaction broadband noise is commonly studied by employing techniques (such as hot-wire anemometry or particle image velocimetry) that allow researchers to measure the mean properties of a fully developed turbulent flow in the near wake region of the aerofoil as well as over it surface. Similarly, the technique that we have employed enables us to study the flow mean properties, however it also offers an additional advantage that is the ability to recreate the temporal-spatial development of the flow. This allows us to demonstrate how the flow changes as it passes through a flow domain of interest. This means that in comparison to more commonly adopted experimental techniques, our technique can provide some additional information on the flow behaviour, such as the origin of flow structures that might be observed. In addition to this, the technique opens up a possibility to study the noise generated by the flow through the use of wavelet analysis of non-stationary signals. As a result, the recreated development of the flow structure can be supplemented by demonstrating the development of the noise signature produced by the same flow. |
| Type Of Material | Improvements to research infrastructure |
| Year Produced | 2018 |
| Provided To Others? | No |
| Impact | The previously described experimental technique has been used to study the mechanism by which trailing edge broadband noise is generated. However, the technique could potentially be used to study any flow phenomena that are related to low speed turbulent flows. |