مهندسی مکانیک مدرس

مهندسی مکانیک مدرس

ارزیابی و پردازش عددی و تجربی جریان غیر دائم حول مدل های دوار استوانه ای با سه صفحه متعامد تحت دوران اجباری

نوع مقاله : پژوهشی اصیل

نویسندگان
سید محمود کیاء 1
منصور نجاتی جهرمی 2
حسن عیسوند 3
1 کارشناسی ارشد، مهندسی مکانیک، تهران، ایران
2 دانشیار، دانشکده مهندسی برق، دانشگاه علوم و فنون هوایی شهید ستاری، تهران، ایران
3 دانشیار، دانشکده مهندسی هوافضا، دانشگاه علوم و فنون هوایی شهید ستاری، تهران، ایران
10.52547/mme.22.11.637
چکیده
به‌طورکلی اجسام در حال دوران (آنتن‌ها، فرفره‌ها، اجسام پرنده دارای دم) همواره با توجه به ابعاد و سرعت‌های دورانی مختلف، گشتاورهای دورانی متفاوتی تولید می‌کنند. در مواردی نیز موجب وارد شدن خسارات زیادی به دیگر تجهیزات می‌شود، لذا می‌بایست از میزان گشتاوری که اجسام دوار در سرعت‌های دورانی مختلف و همچنین در حضور و یا عدم حضور جریان هوا تولید می‌کنند، مطلع شد. با توجه به اهمیت این موضوع، در این مطالعه به تجزیه‌وتحلیل عددی و تجربی جریان غیر دائم حول مدل استوانه‌ای دارای صفحات عمودی تحت دوران اجباری پرداخته‌شده است و هدف اصلی آن، اندازه‌گیری گشتاور اجسام در حال دوران در شرایط حضور جریان باد و همچنین تثبیت دوران در سرعت‌های دورانی ثابت می‌باشد. ابتدا دستگاه اندازه‌گیری گشتاور دورانی آیرودینامیکی ساخته‌شده و سپس مدل استوانه 3 باله‌ای در تونل باد تحت آزمایش قرارگرفته و شبیه‌سازی عددی مدل‌های 3 و 2 باله‌ای نیز در شرایط یکسان آزمایشگاهی توسط نرم‌افزار انسیس فلوئنت انجام گرفت. تطابق خوبی بین نتایج تجربی و عددی مشاهده گردید و حداکثر خطا بین آن‌ها کمتر از 10 درصد ثبت شد که قابل‌قبول می‌باشد. از نتایج شبیه‌سازی مشاهده شد در هر 180 درجه دوران که بیشترین سطح مقطع مدل‌ها در معرض برخورد مستقیم جریان باد قرار می‌گیرد، ماکزیمم گشتاور تولیدی مدل استوانه 2 باله‌ای، 30 درصد بیشتر از ماکزیمم گشتاور تولیدشده توسط مدل 3 باله‌ای می‌باشد. با افزایش سرعت جریان باد از 20 تا 60 متر بر ثانیه، گشتاور دورانی مدل 3 باله‌ای از 4/0 تا 2/1 نیوتن متر که معادل 200 درصد می‌باشد، افزایش می‌یابد.
کلیدواژه‌ها
گشتاور دورانی
مدل استوانه باله دار
سرعت دوران
تونل باد
جریان باد

موضوعات

عنوان مقاله English

Numerical simulation and experimental evaluation of an unsteady flow around forced rotating cylindrical prototype with three orthogonal plates

نویسندگان English

Seyed Mahmood Kia 1
Mansour Nejati jahromi 2
Hasan Isvand 3
1 MSc., Mechanical Engineering, Tehran, Iran
2 Associate Prof., Faculty of electrical engineering, Shahid Sattari Aeronautical University, Tehran, Iran
3 Associate Prof., Faculty of aerospace, Shahid Sattari Aeronautical University, Tehran, Iran
چکیده English

In general, rotating objects always produce different rotational torques according to different dimensions and rotational speeds. In some cases, it can cause a lot of damage to equipment, so it is necessary to be aware of the amount of torque that rotating objects produce at different rotational speeds, as well as in the presence or absence of air flow. in this study, numerical and experimental analysis of non-continuous flow around a cylindrical model with vertical plates under forced rotation is performed and its main purpose is to measure the torque of rotating objects in the presence of wind current also to stabilize rotation. Rotational speeds are constant. First, an aerodynamic torque measuring device was built and then a 3-fin cylindrical model was tested in a wind tunnel, and numerical simulations of 3 and 2 fin models were performed in the same laboratory conditions by Ensys Fluent software. A good agreement was observed between the experimental and numerical results and the maximum error between them was less than 10%, which is acceptable. From the simulation results, it was observed that in every 180 degrees of rotation that the maximum cross section of the models is exposed to direct wind flow, the maximum torque produced by the 2-blade cylindrical model is 30% higher than the maximum torque produced by the 3-blade model. As the wind speed increases from 20 to 60 meters per second, the torque of the 3-fin model increases from 0.4 to 1.2 Nm, which is equivalent to 200%.

کلیدواژه‌ها English

Rotational Torques
Finned cylindrical model
Rotational speed
Wind tunnel
wind flow
[1]. Van Dyke, M., 1982. "An Album of Fluid Motion", 10th Edition, pp. 56-57.
[1]. Van Dyke, M., 1982. "An Album of Fluid Motion", 10th Edition, pp. 56-57.
[2]. Kia, S. M., and Talebi, F., 2018. "Numerical investigation of unsteady flow around a circular cylinder at different reynolds number", 26th Annual International Conference of Iranian Society of Mechanical Engineers, Vol. 3, pp. 4591-4595.
[2]. Kia, S. M., and Talebi, F., 2018. "Numerical investigation of unsteady flow around a circular cylinder at different reynolds number", 26th Annual International Conference of Iranian Society of Mechanical Engineers, Vol. 3, pp. 4591-4595.
[3]. Durante D., Rossi, E., and Graziani, G., 2016. "Numerical simulations of the transition from laminar to chaotic behavior of the planar vortex flow past a circular cylinder", Communications in Nonlinear Science and Numerical Simulation, Vol. 48, pp. 18-38. [DOI:10.1016/j.cnsns.2016.12.013]
[3]. Durante D., Rossi, E., and Graziani, G., 2016. "Numerical simulations of the transition from laminar to chaotic behavior of the planar vortex flow past a circular cylinder", Communications in Nonlinear Science and Numerical Simulation, Vol. 48, pp. 18-38. [DOI:10.1016/j.cnsns.2016.12.013]
[4]. Yeon, Seong Mo., Yang, Jianming., and Stern, Frederick., 2015. "Large-eddy simulation of the flow past a circular cylinder at sub- to super-critical Reynolds numbers", Ocean Research, Vol. 59, pp. 663-675. [DOI:10.1016/j.apor.2015.11.013]
[4]. Yeon, Seong Mo., Yang, Jianming., and Stern, Frederick., 2015. "Large-eddy simulation of the flow past a circular cylinder at sub- to super-critical Reynolds numbers", Ocean Research, Vol. 59, pp. 663-675. [DOI:10.1016/j.apor.2015.11.013]
[5]. Clement R. R., SM., and Maull, D. J., 1975. "The representation of sheets of Vorticity by Discrete Vortices", progress in aerospace science, 16(2), pp. 129-149. [DOI:10.1016/0376-0421(75)90013-5]
[5]. Clement R. R., SM., and Maull, D. J., 1975. "The representation of sheets of Vorticity by Discrete Vortices", progress in aerospace science, 16(2), pp. 129-149. [DOI:10.1016/0376-0421(75)90013-5]
[6]. Stringer, R.M., Zang, J., and Hillis, A.J., 2014. "Unsteady RANS computations of flow around a circular cylinder for a wide range of Reynolds numbers", International Journal of Research and Development, Vol. 87, pp. 1-9. [DOI:10.1016/j.oceaneng.2014.04.017]
[6]. Stringer, R.M., Zang, J., and Hillis, A.J., 2014. "Unsteady RANS computations of flow around a circular cylinder for a wide range of Reynolds numbers", International Journal of Research and Development, Vol. 87, pp. 1-9. [DOI:10.1016/j.oceaneng.2014.04.017]
[7]. Helmoholtz, H., 1858. "Uber integral der hydrodaynamischen gleichunqen welch den wirbelewequngen entsprechen", jounal fur diereine and angewandte mathematic. [DOI:10.1515/crll.1858.55.25]
[7]. Helmoholtz, H., 1858. "Uber integral der hydrodaynamischen gleichunqen welch den wirbelewequngen entsprechen", jounal fur diereine and angewandte mathematic. [DOI:10.1515/crll.1858.55.25]
[8]. Fink, P. T., and soh, W. K., 1974. "Calculation of vortex sheets in unsteady flow and application in ship hydrodynamics", symp on Naval hydrodynamic.
[8]. Fink, P. T., and soh, W. K., 1974. "Calculation of vortex sheets in unsteady flow and application in ship hydrodynamics", symp on Naval hydrodynamic.
[9]. Saffman, P. G., and baker, G. R., 1979, "Vortex interaction", journal of fluid mechanic. [DOI:10.1146/annurev.fl.11.010179.000523]
[9]. Saffman, P. G., and baker, G. R., 1979, "Vortex interaction", journal of fluid mechanic. [DOI:10.1146/annurev.fl.11.010179.000523]
[10]. Saffman. P. G, 1981. "Dynamic of vorticity", journal of fluid mechanic. [DOI:10.1017/S0022112081001511]
[10]. Saffman. P. G, 1981. "Dynamic of vorticity", journal of fluid mechanic. [DOI:10.1017/S0022112081001511]
[11]. Leonard, A., 1980. "Vortex methods for flow simulation", journal of computational physics, Vol 37(3), pp. 289-335. [DOI:10.1016/0021-9991(80)90040-6]
[11]. Leonard, A., 1980. "Vortex methods for flow simulation", journal of computational physics, Vol 37(3), pp. 289-335. [DOI:10.1016/0021-9991(80)90040-6]
[12]. Leonard, A., 1980. "Vortex simulation of three-dimentional spotlike disturbances in a laminar boundary layer", journal of computational physics, Vol 14, pp. 7-12.
[12]. Leonard, A., 1980. "Vortex simulation of three-dimentional spotlike disturbances in a laminar boundary layer", journal of computational physics, Vol 14, pp. 7-12.
[13]. Leonard, A., 1985. "Computing three-dimentional in compressible flows with vortex elements", journal of fluid mechanics, Vol. 17, pp. 523-559. [DOI:10.1146/annurev.fl.17.010185.002515]
[13]. Leonard, A., 1985. "Computing three-dimentional in compressible flows with vortex elements", journal of fluid mechanics, Vol. 17, pp. 523-559. [DOI:10.1146/annurev.fl.17.010185.002515]
[14]. Leonard, A., and Conet, B., 1985. "Two studies in three-dimentional vortex dynamics: A perturbed round jet and an inhomogeneous mixing layer", the Norwegian Inst, Vol. 22, pp. 362-278.
[14]. Leonard, A., and Conet, B., 1985. "Two studies in three-dimentional vortex dynamics: A perturbed round jet and an inhomogeneous mixing layer", the Norwegian Inst, Vol. 22, pp. 362-278.
[15]. Aref, H., 1983. "Integrable chaotic and turbulent vortex motion in two dimensional flows", journal of fluid mechanics, Vol. 15, pp. 345-389. [DOI:10.1146/annurev.fl.15.010183.002021]
[15]. Aref, H., 1983. "Integrable chaotic and turbulent vortex motion in two dimensional flows", journal of fluid mechanics, Vol. 15, pp. 345-389. [DOI:10.1146/annurev.fl.15.010183.002021]
[16]. Joukovski, N. E., 1948. "Attached Vortex", gas mechanic, Vol. 2, pp. 149-168.
[16]. Joukovski, N. E., 1948. "Attached Vortex", gas mechanic, Vol. 2, pp. 149-168.
[17]. Feng, c.c, 1968. "The measurement of vortex included effects in flow past stationary and oscillating circular and d-section cylinders. Master's Thesis, The University of British Columbia, Canada.
[17]. Feng, c.c, 1968. "The measurement of vortex included effects in flow past stationary and oscillating circular and d-section cylinders. Master's Thesis, The University of British Columbia, Canada.
[18]. Umemura, S., Yamaguchi, T., Shiraki, K., 1971. "On the vibration of Cylinders caused by Karman Vortex", Bulletin of Japan Society of Mechanical Engineering, Volume 14, No. 75, pp. 929-936. [DOI:10.1299/jsme1958.14.929]
[18]. Umemura, S., Yamaguchi, T., Shiraki, K., 1971. "On the vibration of Cylinders caused by Karman Vortex", Bulletin of Japan Society of Mechanical Engineering, Volume 14, No. 75, pp. 929-936. [DOI:10.1299/jsme1958.14.929]
[19]. Z, Zabar, 2003. "Electric Machines, Drives", Encyclopedia of Physical Science and Technology, Encyclopedia of Physical Science and Technology, pp.69-95. [DOI:10.1016/B0-12-227410-5/00917-0]
[19]. Z, Zabar, 2003. "Electric Machines, Drives", Encyclopedia of Physical Science and Technology, Encyclopedia of Physical Science and Technology, pp.69-95. [DOI:10.1016/B0-12-227410-5/00917-0]
مهندسی مکانیک مدرس
دوره 22، شماره 11
آبان 1401
صفحه 637-646