The influence of anemometer rotor shape parameters, such as the cups’ front area or their center rotation radius on the anemometer’s performance was analyzed. This analysis was based on calibrations performed on two different anemometers (one based on magnet system output signal, and the other one based on an opto-electronic system output signal), tested with 21 different rotors. The results were compared to the ones resulting from classical analytical models. The results clearly showed a linear dependency of both calibration constants, the slope and the offset, on the cups’ center rotation radius, the influence of the front area of the cups also being observed. The analytical model of Kondo et al. was proved to be accurate if it is based on precise data related to the aerodynamic behavior of a rotor’s cup.

The Bolund experiment has been reproduced in a neutral boundary layer wind tunnel (WT) at scale 1:115 for two Reynolds numbers. All the results have been obtained for an incoming flow from the 270^owind direction (transectBin the Bolund experiment jargon). Vertical scans of the velocity field are obtained using non‐time resolved two components particle image velocimetry. Time‐resolved velocity time series with a three component hot‐wire probe have been also measured for transects at 2 and 5 m height and in the vertical transects at met masts M6, M3 and M8 locations. Special attention has been devoted to the detailed characterization of the inflow in order to reduce uncertainties in future comparisons with other physical and numerical simulations. Emphasis is placed on the analysis of spectral functions of the undisturbed flow and those of the flow above the island. The result's reproducibility and trustworthiness have been addressed through redundancy measurements using particle image velocimetry, two and three components hot‐wire anemometry. The bias in the prediction of the mean speed is similar to the one reported during the Bolund experiment by the physical modellers. However, certain reduction of the bias in the estimation of the turbulent kinetic energy is achieved. The WT results of spectra and cosprectra have revealed a behaviour similar to the full‐scale measurements in some relevant locations, showing that WT modelling can contribute to provide valid information about these important structural loading factors. Copyright © 2013 John Wiley & Sons, Ltd.

Additive manufacturing has profoundly influenced the aerospace industry since its inception, offering unmatched design freedom, cost reduction, rapid prototyping, and enhanced supply-chain efficiency. High-performance polymers like ULTEM™ and PEEK have emerged, known for their strength, temperature resistance, chemical resistance, and lightweight properties. However, the mechanical properties of materials produced through additive manufacturing can vary due to several factors in the printing process, leading to some degree of uncertainty. To address this, the mechanical properties of ULTEM™ 9085 and ULTEM™ 1010 were characterized through mechanical tests. These tests aimed to provide valuable insights into the performance of these materials to be able to run more practical and precise analyses in concurrent design facilities for topological optimization. The results were also compared to materials used in traditional manufacturing methods for components such as flexures and compliant mechanisms. While not fully able to replace metals in high-stress environments, they can be effectively utilized in specific applications. The tests performed contribute to the building of databases that would allow for faster access to critical data that could be applied to a simulation to predict structural performance. This research highlights the potential of additive manufacturing to revolutionize material use in the aerospace sector.

This paper presents the development of the UPMSat-2 sun sensor, from the design to on-orbit operation. It also includes the testing of the instrument, one of the most important tasks that needs to be performed to operate a sensor with precision. The UPMSat-2 solar sensor has been designed, tested, and manufactured at the Universidad Politécnica de Madrid (UPM) using 3D printing and COTS (photodiodes). The work described in this paper was carried out by students and teachers of the Master in Space Systems (Máster Universitario en Sistemas Espaciales—MUSE). The solar sensor is composed of six photodiodes that are divided into two sets; each set is held and oriented on the satellite by its corresponding support printed in Delrin. The paper describes the choice of components, the electrical diagram, and the manufacture of the supports. The methodology followed to obtain the response curve of each photodiode is simple and inexpensive, as it requires a limited number of instruments and tools. The selected irradiance source was a set of red LEDs and halogen instead of an AM0 spectrum irradiance simulator. Some early results from the UPMSat-2 mission have been analyzed in the present paper. Data from magnetometers and the attitude control system have been used to validate the data obtained from the sun sensor. The results indicate a good performance of the sensors during flight, in accordance with the data from the ground tests.

In this paper, the experimental results of an unconventional joined-wing aircraft configuration are presented. The test model uses two different wings, forward and rear, both joined in tandem and forming diamond shapes both in plant and front views. The wings are joined in such a way that it is possible to change the rear wing dihedral angle values and the rear wing sweep angle values in 25 different positions that modify the relative distance and the relative height between the wings. To measure the system aerodynamic coefficients it is necessary to perform wind tunnel tests. The data presented corresponds to the lift, drag and induced drag aerodynamic coefficients, as well as the aerodynamic efficiency and the parameter for minimum required power, from the calculated values of the lift and drag time series measured by a 6-axis force and torque sensor. The results show the influence on the aerodynamic coefficients of the rear wing sweep and dihedral angles parameters. As a main result, it can be concluded that, in general terms, the lift and induced drag aerodynamic coefficients values decrease as both the distance and height between the wings increase, on the other hand, the total drag aerodynamic coefficient decreases if the distance between the wings increases, but nevertheless shows a slight tendency to increase if the height of the rear wing increases, whereas the aerodynamic efficiency and the parameter for minimum required power increase if the distance between the wings increases.