Cranfield University

This paper investigates the take-off performance of a single engine battery-electric aeroplane, using the example of the 300kg Sherwood eKub. It shows analysis of take-off performance of such an aeroplane must include as a minimum two new parameters not normally considered: time at full throttle and state of charge. It was shown in both ground and flight test that the state of available power reduces both as the throttle is fully open, and as battery charge is consumed, although recovers partially when power is reduced for a period. It is possible to schedule take-off performance as a function of the usual parameters plus state of charge. Because of the reducing climb performance with use of state of charge, and the requirement in airworthiness standards for minimum climb performance being available, it becomes necessary to introduce the concept of minimum-indicated state of charge for take-off, SoCi_MTO; means to calculate that are shown for compliance with both microlight aeroplane standards and larger aeroplane standards, and the calculations are demonstrated for the eKub. Conclusions are also drawn about the use of commercial products SkyDemon and Google Earth for recording and analysing aeroplane performance data.

G.B. Gratton; T. Delaney; B. Zaghari; G. Kendall. Take-off performance of a single engine battery-electric aeroplane. The Aeronautical Journal 2024, 1 -18.

G.B. Gratton, T. Delaney, B. Zaghari, G. Kendall. Take-off performance of a single engine battery-electric aeroplane. The Aeronautical Journal. 2024; ():1-18.

G.B. Gratton; T. Delaney; B. Zaghari; G. Kendall. 2024. "Take-off performance of a single engine battery-electric aeroplane." The Aeronautical Journal , no. : 1-18.

Sugarcane is a high-impact crop used in the majority of global sugar production, with India being the second largest global producer. Understanding the timing and length of sugarcane growth stages is critical to improving the sustainability of sugarcane management. Earth observation (EO) data have been shown to be sensitive to the variation in sugarcane growth, but questions remain as to how to reliably extract sugarcane phenology over wide areas so that this information can be used for effective management. This study develops an automated approach to derive sugarcane growth stages using EO data from Landsat-8 and Sentinel-2 satellite data in the Indian state of Andhra Pradesh. The developed method is then evaluated in the State of Telangana. Normalised difference vegetation index (NDVI) EO data from Landsat-8 and Sentinel-2 were pre-processed to filter out clouds and to harmonise sensor response. Pixel-based cloud filtering was selected over filtering by scene in order to increase the temporal frequency of observations. Harmonising data from two different sensors further increased temporal resolution to 3–6 days (70% of sampled fields). To automate seasonal decomposition, harmonised signals were resampled at 14 days, and low-frequency components, related to seasonal growth, were extracted using a fast Fourier transform. The start and end of each season were extracted from the time series using difference of Gaussian and were compared to assessments based on visual observation for both Unit 1 (R² = 0.72–0.84) and Unit 2 (R² = 0.78–0.82). A trapezoidal growth model was then used to derive crop growth stages from satellite-measured phenology for better crop management information. Automated assessments of the start and the end of mid-season growth stages were compared to visual observations in Unit 1 (R² = 0.56–0.72) and Unit 2 (R² = 0.36–0.79). Outliers were found to result from cloud cover that was not removed by the initial screening as well as multiple crops or harvesting dates within a single field. These results demonstrate that EO time series can be used to automatically determine the growth stages of sugarcane in India over large areas, without the need for prior knowledge of planting and harvest dates, as a tool for improving sustainable production.

Neha Joshi; Daniel M. Simms; Paul J. Burgess. Automating the Derivation of Sugarcane Growth Stages from Earth Observation Time Series. Remote Sensing 2024, 16, 4244 .

Neha Joshi, Daniel M. Simms, Paul J. Burgess. Automating the Derivation of Sugarcane Growth Stages from Earth Observation Time Series. Remote Sensing. 2024; 16 (22):4244.

Neha Joshi; Daniel M. Simms; Paul J. Burgess. 2024. "Automating the Derivation of Sugarcane Growth Stages from Earth Observation Time Series." Remote Sensing 16, no. 22: 4244.

The operation of vertical axis wind turbines (VAWTs) to generate low-carbon electricity is growing in popularity. Their advantages over the widely used horizontal axis wind turbine (HAWT) include their low tip speed, which reduces noise, and their cost-effective installation and maintenance. A Farrah turbine equipped with 12 blades was designed to enhance performance and was recently the subject of experimental investigation. However, little research has been focused on turbine configurations with more than three blades. The objective of this study is to employ numerical methods to analyse the performance of the Farrah wind turbine and to validate the findings in comparison with experimental results. The investigated blade pitch angles included both positive and negative angles of 7, 15, 20 and 40 degrees. The k-ω SST model with the sliding mesh technique was used to perform simulations of a 14.4 million element unstructured mesh. Comparable trends of power output results in the experimental investigation were obtained and the assumptions of mechanical losses discussed. Wake recovery was determined at an approximate distance of nine times the turbine diameter. Two large complex quasi-symmetric vortical structures were observed between positive and negative blade pitch angles, located in the near wake region of the turbine and remaining present throughout its rotation. It is demonstrated that a number of recognised vortical structures are transferred towards the wake region, further contributing to its formation. Additional notable vortical formations are examined, along with a recirculation zone located in the turbine’s core, which is described to exhibit quasi-symmetric behaviour between positive and negative rotations.

Chris Sungkyun Bang; Zeeshan A. Rana; Simon A. Prince. CFD Analysis on Novel Vertical Axis Wind Turbine (VAWT). Machines 2024, 12, 800 .

Chris Sungkyun Bang, Zeeshan A. Rana, Simon A. Prince. CFD Analysis on Novel Vertical Axis Wind Turbine (VAWT). Machines. 2024; 12 (11):800.

Chris Sungkyun Bang; Zeeshan A. Rana; Simon A. Prince. 2024. "CFD Analysis on Novel Vertical Axis Wind Turbine (VAWT)." Machines 12, no. 11: 800.