Aerodynamic design, which aims at developing the outer shape of the aircraft while meeting several contrasting requirements, demands an accurate and reliable aerodynamic database. Computing forces and moments with the highest level of delity is a prerequisite, but practically limited by wall clock time and available computing resources. An ecient and robust approach is therefore sought after. This study investigates two design of experiments algorithms in combination with surrogate modelling. In traditional design of experiments, the samples are selected a priori before running the numerical explorative campaign. It is wellknown that this may result in either poor prediction capabilities or high computational costs. The second strategy employs an adaptive design of experiments algorithm. As opposed to the former, this is a selflearning technique that iteratively: i) identies the regions of the design space that are characterised by stronger nonlinearities; * First corresponding author. Email: A.Da-Ronch@soton.ac.uk Preprint submitted to SCAD 2016 August 10, 2016 and ii) select the new samples in order to maximise the information content associated with the simulations to be performed during the next iteration. In this work, the Reynoldsaveraged NavierStokes equations are solved around a complete aircraft conguration. A representative ight envelope is created taking the angle of attack and Mach number as design parameters. The adaptive strategy is found to perform better than the traditional counterpart. This is quantied in terms of the sum of the squared error between the surrogate model predictions and CFD results. For the pitch moment coecient, which shows strong nonlinearities, the error metric using the adaptive strategy is reduced by about one order of magnitude compared to the traditional approach. Furthermore, the proposed adaptive methodology, which is employed on a high performance computing facility, requires no extra costs or complications than a traditional methodology.

<p>The basis of this work was to understand the generation of lift and thrust of a flapping bi-wing ornithopter, which is influenced by its geometrical, dynamic, kinematic and aerodynamic features by following a generic approach in order to identify and mimic the mechanisms. As further development of earlier work, three-dimensional rigid thin wing is considered in flapping and pitching motion using strip theory and two-dimensional unsteady aerodynamics for idealized wing in pitching and flapping oscillations with phase lag. Later, parametric study is carried out to attain a complete cycle’s lift and thrust physical characteristics for evaluating the plausibility of the aerodynamic model and for the synthesis of an ornithopter model with simplified mechanism. Further investigation is conducted to identify individual contribution of generic motion towards the flight forces. Results are assessed in comparison with existing theoretical and experimental results as appropriate.</p>

In this study, characterization of measured electric fields due to lightning channel was done. Likewise, previous studies on this case were reviewed and discussed accordingly. Furthermore, preliminary breakdown was done in detail and it was indicated on the real measured electric fields and the results were discussed. The behavior of preliminary breakdown signal was observed. This study shows that it will be easier to design filtering of the preliminary breakdown. The result show compelling agreement with theoretical predictions and significant improvement over previous effort by Clarence and Malan, Weidman and Krider and Rakov , et al. the work presented here has profound implications for future studies of Preliminary Breakdown and may one day help solve the problem of designing protection level for Electrical Engineers. The results show that the occurrence of PBP is in between 2 to 10 milliseconds before return stroke as agreed with Clerence and Malan.

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