Papers by Rolf Luchsinger
Energies
Inflatable wings are of interest for applications where low weight, compact transport volume, and... more Inflatable wings are of interest for applications where low weight, compact transport volume, and easy set-up are important. Examples are unmanned aerial vehicles with inflatable wings, paragliders and softkites for sport or airborne wind-energy applications. In this paper, a new method of designing and fabricating conformable inflatable wings by Jacquard three-dimensional weaving is presented. Depending on the weaving pattern, plane-parallel, tapered, or even curved structures can be produced. An analytical framework was developed to determine the shapes of pressurized structures produced by Jacquard weaving. Based on this theory, several design patterns suitable for inflatable wings are proposed. It is shown that the structural efficiency of the woven structure is identical to the structural efficiency of a cylinder. To validate the concept, different wing prototypes were built with the methods used for the mass production of airbags. The new method allows for the cost-efficient f...
This panel discussion also includes a short presentation by Amanda Boekholt, Swiss Federal Office... more This panel discussion also includes a short presentation by Amanda Boekholt, Swiss Federal Office of Civil Aviation (FOCA), about the U Space set of federated services.
Airborne Wind Energy, 2018
Pumping cycle kite power has attracted considerable interest over the last years with several sta... more Pumping cycle kite power has attracted considerable interest over the last years with several start-ups and research teams investigating the technology. While all these groups produce electrical power with a ground-based generator in a cyclic process, there is no consent about the shape, structure and control of the flying object. In particular the launching and landing strategy has not been settled yet. TwingTec has followed a pragmatic approach focusing on the flying part of the system. The spin-off from Empa and FHNW has developed over the last years in close collaboration with leading research institutes from Switzerland the twing, an acronym for tethered wing. The guiding principle behind the design of the twing was to combine the light weight property of a kite with the aerodynamic properties of a glider plane. Launching and landing was solved by integrating rotors into the structure allowing the twing to hover. Launching, transition into crosswind, autonomous power production, transition into hover and landing has been demonstrated with the current small-scale test system.
This paper shows different tools and approaches that can be useful for the definition of the desi... more This paper shows different tools and approaches that can be useful for the definition of the design of pneumatic structures. Some of these tools have been applied for the design of a Tensairity® hull.
The purpose of the on-going project DYNASUIT is to design a new intravehicular body suit for coun... more The purpose of the on-going project DYNASUIT is to design a new intravehicular body suit for countermeasure purposes, including state of the art technologies in artificial muscles, body monitoring and biofeedback. This paper focuses on the concepts, designs and testing of the artificial muscles subsystem. Based on a preliminary analysis and a selection of the most promising scenarios, two actuation technologies have been selected for deeper analysis in the project, namely electro-active polymers (EAP) and sigma pneumatic actuators. The paper describes the design and the expected performances of each of the actuation technologies in the suit. The physical demonstrators built during the activity in order to validate the designs and characteristics of the actuators in the context of DYNASUIT, as well as the associated results, are presented. These outputs will be used in the following of the activity to support the detailed design of the full countermeasure suit.
Journal of Structural Engineering, 2017
AbstractThe dynamic analysis of a pneumatic beam structure, termed the Tensairity girder, is expe... more AbstractThe dynamic analysis of a pneumatic beam structure, termed the Tensairity girder, is experimentally, numerically, and analytically studied. The structural concept of Tensairity relies on the combination of an airbeam with conventional struts, which leads in a light-weight structure of significant load-bearing capacity. By focusing on the analysis of the dynamic response of this structure, the objective of this work is to determine the pressure-dependent modal characteristics of the pneumatic beam and to couple these with the associated material properties. Based on the results of a modal identification procedure, relying on hammer and white noise excitation tests, a finite-element (FE) model is updated to reflect the actual system response. This procedure reveals the membrane’s shear modulus as the material property that more heavily relies upon the pressure level of the Tensairity girder. The experimental and numerical investigations indicate that the dynamic behavior of the beam can be expressed...
Thin-Walled Structures, 2016
Steel Construction, 2015
This paper provides a detailed overview of the design and construction of a series of temporary p... more This paper provides a detailed overview of the design and construction of a series of temporary pavilions based on the Tensairity ® principle. The pavilions are currently used in the Superbike racing category (Ducati Superbike Team), for the Audi tron Sailing Series, the ISAF Sailing World Cup and for other temporary events (3KIT pavilion). The paper describes the Tensairity ® principle, the architectural and structural design of the pavilions, the manufacturing of the components and the assembly of the Tensairity ® roofs.
An analytical model for the deflection of a symmetric, spindle shaped Tensairity girder under hom... more An analytical model for the deflection of a symmetric, spindle shaped Tensairity girder under homogenous load is proposed which can be solved analytically. The results are compared to FEM predictions for a specific Tensairity girder. Further simplifications of the analytical solution lead to a simple relation for the deflection of the Tensairity girder, which reveals the importance of the elasticity of the chords relative to the air pressure in the inflated hull. Such simple models are crucial to understand the basic principles of Tensairity and provide the engineer with easy rules to estimate the load-deflection behaviour of this new light weight structure.
48th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 2007
Airborne Wind Energy, 2013
Simple analytical models for a pumping cycle kite power system are presented. The theory of cross... more Simple analytical models for a pumping cycle kite power system are presented. The theory of crosswind kite power is extended to include both the traction and retraction phase of a pumping cycle kite power system. Dimensionless force factors for the reel out and reel in phase are introduced which describe the effi ciency of the system. The optimal reel out and reel in speed of the winch is derived where the cycle power becomes maximal. These optimal speeds are solely determined by the ratio of the force factors. Scenarios for wind speeds higher than the nominal wind speed are considered and power curves for the pumping cycle kite power system derived. The average annual power for a given wind distribution function allows to estimate the annual energy production of the pumping cycle kite power system. The role of the elevation angle of the tether is highlighted and a simple model to demonstrate the infl uence of the kite mass on the power output is discussed.
The purpose of the DYNASUIT project is to design a new intravehicular body suit for countermeasur... more The purpose of the DYNASUIT project is to design a new intravehicular body suit for countermeasure purposes, including state of the art technologies in artificial muscles, body monitoring and biofeedback. This paper presents the outputs of the first phase of this on-going activity. First, the weightlessness effects of microgravity on the body and the current countermeasure solutions are described. The main potential scenarios for DYNASUIT are then described, followed by details of the preliminary concepts and associated technologies for bio-monitoring and artificial muscles.
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Papers by Rolf Luchsinger