DSpace Collection:https://hdl.handle.net/2440/10882024-03-28T08:34:25Z2024-03-28T08:34:25ZCo-located offshore wind–wave energy systems: Can motion suppression and reliable power generation be achieved simultaneously?Meng, F.Sergiienko, N.Ding, B.Zhou, B.Silva, L.S.P.D.Cazzolato, B.Li, Y.https://hdl.handle.net/2440/1403122024-01-08T02:06:09Z2023-01-01T00:00:00ZTitle: Co-located offshore wind–wave energy systems: Can motion suppression and reliable power generation be achieved simultaneously?
Author: Meng, F.; Sergiienko, N.; Ding, B.; Zhou, B.; Silva, L.S.P.D.; Cazzolato, B.; Li, Y.
Abstract: Floating offshore wind turbines (FOWTs) present a cost-competitive advantage over their fixed-bottom counterparts, but also have technical challenges of achieving the desired stability and power reliability of the wind turbine. It is believed that co-locating of wave energy converters (WECs) and a FOWT can be the solution to these challenges. However, as the power generation of WECs is strongly associated with their hydrodynamic response, their addition tends to have a detrimental effect on the FOWT’s performance. To address this challenge, this paper proposes a framework for combining a FOWT with a small wave array that will make it possible to simultaneously achieve a reliable overall power production, and minimise the motion of a floating platform. It is done by properly controlling the hydrodynamic coupling between FOWT and WEC via a model predictive control approach. The results demonstrate that this novel approach manages to achieve platform stability and power reliability simultaneously, although it might require to collaborate with an aerodynamic control at high wind speeds. This work can be used as a guidance for operation of co-located wind–wave power systems.2023-01-01T00:00:00ZDesign considerations for a three-tethered point absorber wave energy converter with nonlinear coupling between hydrodynamic modesTran, N.Sergiienko, N.Y.Cazzolato, B.S.Ghayesh, M.H.Arjomandi, M.https://hdl.handle.net/2440/1403062024-01-05T03:01:23Z2022-01-01T00:00:00ZTitle: Design considerations for a three-tethered point absorber wave energy converter with nonlinear coupling between hydrodynamic modes
Author: Tran, N.; Sergiienko, N.Y.; Cazzolato, B.S.; Ghayesh, M.H.; Arjomandi, M.
Abstract: Multi-mode Wave Energy Converters (WECs) are designed to harvest energy simultaneously from multiple hydrodynamic modes, thereby maximising power absorption. The behaviour of each mode must be carefully considered, given that hydrodynamic and geometric coupling between modes can lead to severe reductions in power if improperly designed. This study aims to investigate how the design of a planar three-tethered WEC can be used to tune the surge, heave and pitch hydrodynamic modes to achieve maximum power absorption. The effect of various tether arrangement and mass distribution design parameters on the performance of a WEC subjected to both geometric and hydrodynamic nonlinearities was investigated. Results indicated that, to absorb the most power in regular waves, the tether configuration should be adjusted such that the surge and heave dominant rigid body modes are resonant with the incident wave. Geometric nonlinearities associated with the tether arrangement were found to cause sub-harmonic excitations which severely compromised device performance, with further reductions in power when nonlinear hydrodynamics were considered. In irregular waves, the optimal design became more strongly driven by performance in surge. Overall, maximum power was achieved when all three tethers were attached close to one another on the bottom of the buoy.2022-01-01T00:00:00ZThe effect of blade depth ratio on the performance of in-stream water wheelsBrandon-Toole, M.Birzer, C.Kelso, R.https://hdl.handle.net/2440/1402852023-12-21T03:04:23Z2023-01-01T00:00:00ZTitle: The effect of blade depth ratio on the performance of in-stream water wheels
Author: Brandon-Toole, M.; Birzer, C.; Kelso, R.
Abstract: The power characteristics of an in-stream water wheel were measured experimentally to explore the influence of the blade depth ratio. The blade depth ratio has a significant effect on the performance of in-stream water wheels, but its influence has been overlooked throughout the literature. It was determined that the blade depth ratio has a greater impact on the power production than the number of blades at all tip-speed ratios. However, the variation between the maximum and minimum available power is greater at high blade depth ratios, so it is important to understand the relationship between the blade depth ratio and tip-speed ratio. Analysis of velocity triangles determined that at the inlet and outlet, the turbine blade contributes negatively to net torque. This effect is increased at higher blade depth ratios. It was also determined that the peak dry coefficient of power is linearly proportional to the blade submergence ratio, which is a measure of the total submerged blade area. This investigation progresses research in this area by highlighting an overlooked parameter and experimentally determining its influence on power characteristics.
Description: Available online 10 November 20232023-01-01T00:00:00ZA Theoretical Review of Rotating Detonation EnginesShaw, I.J.Kildare, J.A.C.Evans, M.J.Chinnici, A.Sparks, C.Rubaiyat, S.N.H.Chin, R.C.Medwell, P.R.https://hdl.handle.net/2440/1400602023-12-04T23:37:11Z2021-01-01T00:00:00ZTitle: A Theoretical Review of Rotating Detonation Engines
Author: Shaw, I.J.; Kildare, J.A.C.; Evans, M.J.; Chinnici, A.; Sparks, C.; Rubaiyat, S.N.H.; Chin, R.C.; Medwell, P.R.
Editor: Rao, S.P.
Abstract: Rotating detonation engines are a novel device for generating thrust from combustion, in a highly efficient, yet mechanically simple form. This chapter presents a detailed literature review of rotating detonation engines. Particular focus is placed on the theoretical aspects and the fundamental operating principles of these engines. The review covers both experimental and computational studies, in order to identify gaps in current understanding. This will allow the identification of future work that is required to further develop rotating detonation engines.2021-01-01T00:00:00Z