Tethered "kiteplane" design for the Laddermill project

The Laddermill is an innovative concept for generating energy from wind using large kite-like wings on a tether. The wings are able to fly in both the regime of airplanes and kites. We therefore call these structures "kiteplanes". By providing a recurring motion with a large lift during ascending and a lower lift during descending, energy can be generated. The Laddermill is currently under development at the Faculty of Aerospace Engineering at the Delft University of Technology. This paper presents the design and testing of a 3 meter span scaled model of a laddermill kiteplane. First, an introduction to the laddermill will be given. Then the sail wing will be outlined. Both aerodynamic and structural aspects will be addressed. The next section deals with the stability of the kiteplane. The eigenvalues are determined which govern the motions of the kiteplane. After the theory, the paper will go into the building of the kiteplane and the flight testing. The conclusion will go into the relevance of this wing concept to the laddermill and the eventual generation of sustainable energy.Aerospace Engineerin

Investigation of Vestibular adaptation to changing gravity levels on earth

Background: During the first days in space 50-80 of the astronauts suffer from the Space Adaptation Syndrome (SAS). The symptoms of SAS, like nausea and dizziness, are especially provoked by head movements. Although it is generally agreed that the vestibular system is involved in causing SAS, no distinct clue has been found to its aetiology, the individual's susceptibility, and its predictability. Susceptibility to SAS does not correlate with susceptibility to motion sickness on earth. However, astronauts have mentioned close similarities between the symptoms of SAS and the symptoms they experienced after a 3G centrifuge run on earth (Sickness Induced by Centrifugation, SIC). This suggests that a gravity transition from 3 to 1G provokes the same effects as a transition from 1 to 0G, implicating a general vestibular adaptation mechanism to changing G-levels. Objectives: This study aims to further the insight in the process of vestibular adaptation to G-transitions. Two important parameters are the perception of body motion and attitude during the adaptation process. A second objective is to investigate the correlation between susceptibility to SAS and SIC. Methods: During several space missions the correlation between susceptibility to SIC and SAS has been investigated [1]. Since head movements are shown to be provocative, this provocativeness was taken as an indicator for SIC and SAS susceptibility. Susceptibility to SIC was assessed after a 1 h centrifuge run at 3Gx, susceptibility to SAS during the mission. Within the framework of the 2004 Delta Mission, vestibular adaptation was addressed for 2 astronauts in four vestibular function tests carried out about a 1h 3Gx centrifuge run (-1h, +0h, +2h, +4h). The tests included motion perception and sickness ratings, stabilometry in a tilting room, subjective vertical measurements in a tilting chair, and eye movement registrations (Listing's plane). Results: At present, a total of 9 astronauts were tested both in the centrifuge and in space. We found a positive correlation between susceptibility to SIC and SAS: 3 astronauts were both susceptible to SIC and to SAS, 6 were not (i.e. no cross-findings have been observed yet). The vestibular function tests showed that postural stability was decreased after the centrifuge run in one SIC-susceptible subject and unaffected in the other non-susceptible subject. So far we have not observed a clear effect of the centrifuge run on tilt perception. Conclusion: The positive correlation between susceptibility to SIC and to SAS is in agreement with the hypothesis that SIC and SAS share the same underlying mechanism. This makes long duration centrifugation a valuable tool for investigating vestibular adaptation to G-transitions on earth. The gained knowledge can be implemented in a general model of vestibular adaptation. The vestibular tests showed that several vestibular driven processes are affected by the gravity transition. However, further testing is needed to identify key adaptation parameters

Space sickness on Earth

During the first days in space, i.e., after a transition from 1G to 0G, more than 50 of the astro- (and cosmonauts) suffer from the Space Adaptation Syndrome (SAS).The symptoms of SAS, like nausea and dizziness, are especially provoked by head movements. Astronauts have mentioned close similarities between the symptoms of SAS and the symptoms they experienced after a 1 hour centrifuge run on Earth, i.e., after a transition from 3G to 1G (denoted by Sickness Induced by Centrifugation, SIC). During several space missions, we related susceptibility to SAS and to SIC in 11 astronauts and found 4 of them being susceptible to both SIC and SAS, and 7 being not susceptible to SIC nor to SAS. This correspondence in susceptibility suggests that SIC and SAS share the same underlying mechanism. To further study this mechanism, several vestibular parameters have been investigated (e.g. postural stability, vestibularly driven eye movements, subjective vertical). We found some striking changes in individual cases that are possibly due to the centrifuge run. However, the variability between subjects generally is very large, making physiological links to SIC and SAS still hard to find

Space sickness on earth

During the first days in space, i.e., after a transition from 1G to 0G, more than 50% of the astro- (and cosmonauts) suffer from the Space Adaptation Syndrome (SAS).The symptoms of SAS, like nausea and dizziness, are especially provoked by head movements. Astronauts have mentioned close similarities between the symptoms of SAS and the symptoms they experienced after a 1 hour centrifuge run on Earth, i.e., after a transition from 3G to 1G (denoted by Sickness Induced by Centrifugation, SIC). During several space missions, we related susceptibility to SAS and to SIC in 11 astronauts and found 4 of them being susceptible to both SIC and SAS, and 7 being not susceptible to SIC nor to SAS. This correspondence in susceptibility suggests that SIC and SAS share the same underlying mechanism. To further study this mechanism, several vestibular parameters have been investigated (e.g. postural stability, vestibularly driven eye movements, subjective vertical). We found some striking changes in individual cases that are possibly due to the centrifuge run. However, the variability between subjects generally is very large, making physiological links to SIC and SAS still hard to find

Space sickness on earth

During the first days in space, i.e., after a transition from 1G to 0G, more than 50% of the astro- (and cosmonauts) suffer from the Space Adaptation Syndrome (SAS).The symptoms of SAS, like nausea and dizziness, are especially provoked by head movements. Astronauts have mentioned close similarities between the symptoms of SAS and the symptoms they experienced after a 1 hour centrifuge run on Earth, i.e., after a transition from 3G to 1G (denoted by Sickness Induced by Centrifugation, SIC). During several space missions, we related susceptibility to SAS and to SIC in 11 astronauts and found 4 of them being susceptible to both SIC and SAS, and 7 being not susceptible to SIC nor to SAS. This correspondence in susceptibility suggests that SIC and SAS share the same underlying mechanism. To further study this mechanism, several vestibular parameters have been investigated (e.g. postural stability, vestibularly driven eye movements, subjective vertical). We found some striking changes in individual cases that are possibly due to the centrifuge run. However, the variability between subjects generally is very large, making physiological links to SIC and SAS still hard to find

Nuclear Structure Effects in the Quasi-Continuum Deexcitation Process of 152Dy and 156Dy Nuclei Produced in Complete and Incomplete Fusion Reactions

Intensities and energy dependent multiplicity distributions of γ-rays have been measured for 152Dy and 156Dy nuclei populated in (12C, xn) and (12C, αxn) reactions at E = 70-101 MeV. The relative population of the yrast states in 156Dy is found to be almost independent of the input angular momentum, which is not the case for 152Dy. In the latter nucleus the yrast states up to spin values close to the maximum input angular momentum are strongly populated whereas in the former the transition intensities decrease very rapidly with increasing level spin. Quasi-continuum feeding cascades in 156Dy are found to have considerably higher multiplicity than those in 152Dy at comparable input angular momentum. These features can be understood in 156Dy by assuming the existence of a number of collective bands which funnel the γ-ray deexcitation below the entry region away from the high spin yrast states whereas in 152Dy short γ-ray cascades feed directly the yrast states. The entry regions in 156Dy have been determined as a function of bombarding energy for the (12C, 6n) reaction. A decrease of the entry angular momentum above 90 MeV beam energy is found and explained by the existence of strong competing (12C, αxn) incomplete fusion reaction channels. Similar γ-ray sidefeeding patterns and multiplicity distributions for yrast states are observed in 12C induced complete (CF) and incomplete fusion (ICF) reactions leading to 156Dy. However, the data for quasi-continuum feeding multiplicites indicate a more narrow initial angular momentum distribution for ICF than for CF reactions. The mean initial angular momentum for ICF is found to be about 10 h higher than the one for CF and it is close to the critical angular momentum for CF as deduced from a simple reaction model