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19/09/2016 How Ornithopters Fly Calculation Tools http://www.ornithopter.de/english/calculation.htm 1/2 Cover picture of the handbook Force progression in principle Force calculation scheme for flapping wings Calculation tools for ornithopter models There is no common calculation method for flapping wings. In every source of information different methods are being described. All Orni calculation tools given below are based on the calculation method specified in the handbook „How Ornithopters Fly“. Particularly, the power and the twisting of the wing at stationary flight situations can determinate with it. Furthermore, the calculation method permits an approximate quantitative specification of dynamics and aerodynamics of profiled flapping wings, at least. Primarily, the numerical comparison of various factors influencing of flapping wings. Profiled flapping wings and quasistationary flow conditions are presumed. Therefore, calculations only lead to useful results for a fast forward flight with a relatively low flapping frequency (large birds, flying with lift). The mathematical models are only executable with the respective software applications. „Orni 1“ Simple calculation tool to describe the wing twisting The equations of the handbook are used in a small MSEXCEL calculation tool: Download Orni 1 (format xls, with a short instruction in English rel. 3.4, 0.2 MB) Download Orni 1 (format xlsx, with a short instruction in English rel. 3.4, 0.1 MB) This tool primarily allows the calculation of wing twisting at given wing data. The additional calculation of data of the flying model is highly simplified. The detailed calculation of the force progression during a flapping cycle has been replaced by assuming a sinusoidal progression of the force. Thereby coupling of stroke motion and twisting remains unconsidered. Only the reference line (as gliding flight) and the amplitude of the sine halfwave (in the center of each wing stroke) are calculated. With that, the area under the curve progression or the size of a force is calculable. „Orni 2“ Calculation method for ornithopter models The basic calculation method of the handbook „How Ornithopters Fly“ is reconstructed step by step. Many of the itemised equations are generated with accompanying text, diagrams and pictures. The abidance of the operational range of the lift coefficient of the used airfoil is automatically warranted in the calculation tool. Also, the setting of balance of forces during flight happens in a simple way. Therefore, one can certainly achieve the flight data of the chosen model configuration. For the construction of a flapping wing model the calculation method describes various force and moment developments at the wing. Furthermore, the required power and above all the wing twisting along the span are being calculated. http://www.ornithopter.de/grafik/rechnung/titelbild.jpg http://www.ornithopter.de/english/images/calculation/principle.gif http://www.ornithopter.de/english/images/calculation/calculation.gif http://www.ornithopter.de/english/handbook.htm http://www.ornithopter.de/english/principle.htm#strong http://www.ornithopter.de/english/data/orni1_en.xls http://www.ornithopter.de/english/data/orni1_en.xlsx http://www.ornithopter.de/english/images/calculation/sinusoidal.gif http://www.ornithopter.de/english/handbook.htm 19/09/2016 How Ornithopters Fly Calculation Tools http://www.ornithopter.de/english/calculation.htm 2/2 Web Page for taking a look PDF file for printing Spreadsheet for Mathcaduser Orni2 rel. 3.3 orni2.htm 1.7 MB orni2.pdf 317 KB orni2.xmcdz 1.8 MB Airfoil CLARKY rel. 1.2 clark_y.htm 270 KB clark_y.pdf 56 KB clark_y.xmcdz 257 KB Airfoil SD7062PT sd7062pt.htm 320 KB sd7062pt.pdf 60 KB sd7062pt.xmcdz 320 KB Crank drive k_antrieb.htm 450 KB k_antrieb.pdf 110 KB k_antrieb.xmcdz 500 KB Web Page for taking a look PDF file for printing Spreadsheet for Mathcaduser Orni3 rel. 1.3 orni3.htm 665 KB orni3.pdf 130 KB orni3.xmcdz 667 KB (use airfoil programs above mentioned) The calculation tool was written (in German) with the software „Mathcad“. Because of the volume of data and pages it requires a little familiarisation. „Orni 3“ Mathematical model for ornithopters This tool is based on the calculation tool Orni 2. Here, gliding and power flights of a flapping wing model can be analysed singly and in series. To calculate an ornithopter model it is specified by diverse input parameters at first. One of these is defined as an area variable. In the chosen data area one then receives the data of flight and drive, while automatically keeping the data of the airfoil and the balance of forces. Since there are only a few specifications included, the calculation tool Orni 2 beforehand should be known. The calculation tool was written with the software „Mathcad“ (in German). The here listed calculation tools are too understood as open source software. Therefore, everybody is enabled to take an insight look in the calculation method. Everyone has the permission to relay, vary and particularly to correct and improve this source code. Comparison of the transport performance of a swan with flying models The flight performance of a mute swan is compared with the performances of a propeller and a flapping wing model. Download comparison.xlsx (Excel table, 28 kB) The mute swan consume the most energy. Particularly, this is due to the small efficiency of the muscles. Instead, the swan has the advantage that his body fat provides a relatively high density of energy storage. In the calculation tools flapping wing models are a little bit more effective than propeller models. Also the flapping wing model of the handbook is compared with an according propeller model. http://www.ornithopter.de/orni2.htm http://www.ornithopter.de/daten/orni/orni2.pdf http://www.ornithopter.de/daten/orni/orni2.xmcdz http://www.ornithopter.de/clark_y.htm http://www.ornithopter.de/daten/orni/clark_y.pdf http://www.ornithopter.de/daten/orni/clark_y.xmcdz http://www.ornithopter.de/sd7062pt.htm http://www.ornithopter.de/daten/orni/sd7062pt.pdf http://www.ornithopter.de/daten/orni/sd7062pt.xmcdz http://www.ornithopter.de/k_antrieb.htm http://www.ornithopter.de/daten/orni/k_antrieb.pdf http://www.ornithopter.de/daten/orni/k_antrieb.xmcdz http://www.ornithopter.de/orni3.htm http://www.ornithopter.de/daten/orni/orni3.pdf http://www.ornithopter.de/daten/orni/orni3.xmcdz http://www.ornithopter.de/english/data/comparison.xlsx
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