تعيين ميراگر پيچشي مناسب جهت كاهش دامنه ارتعاشات موتور هواپيماهاي فوق سبك

Determination of appropriate torsional damper for reduction of vibrations amplitude of ultralight aircrafts engine

در اين مقاله به تعيين ميراگر پيچشي مناسب براي موتور هواپيماهاي فوق سبك و ميزان تأثير آن‌ ها در كاهش ارتعاشات با تركيب سه روش تجربي، تحليل و عددي پرداخته ‌شده است. ابتدا با تحليل ديناميكي و كد نويسي در نرم ‌افزار متلب، گشتاورهاي سيستم و فشار گاز پيستون با كمتر از 2 درصد اختلاف با نتايج تجربي اعتبارسنجي شدند. سپس حداكثر ميزان جابجايي زاويه ‌اي در بالاترين دور، از روش عددي و تحليلي صحت ‌سنجي و فركانس‌ هاي طبيعي به دست آمدند. در نهايت معادله‌ تعيين ضريب ميرايي، استخراج شد. نتايج نشان داد كه استفاده از ميراگر تا 40 درصد از دامنه ارتعاشات سيستم مي كاهد.

These days, regarding to advanced technologies, the use of ultralight aircraft for transportation and goods movement has been attended by industries and people. One of the major challenges for ultralight aircraft designers is related to reduction of engine vibrations. In this paper, determination of torsional damper for this aircraft engine types and their effect on reducing vibrations by combining three experimental, analytical and numerical methods are discussed. Starting with dynamic analysis and coding in MATLAB software, the system gas pressure and torque were validated with experimental results with less than 2% differences. Then the amount of angular displacement was validated at maximum rotating velocity with 1.86% difference by numerical and analytical methods, then the natural frequencies of system were obtained. Finally, the equation was extracted in order to determine the appropriate damping coefficient and its characteristics were determined. The results showed that using the damper reduces the system vibrations amplitude up to 40%.