دانشگاه صنعتی امیرکبیر نشریه مهندسی مکانیک امیرکبیر 2008-6032 50 2 2018 06 22 Minimization of Rate of Heat Transfer from Rectangular Cavities with Free Convection in Various Aspect Ratios for Finding Characteristics of an Array of Adiabatic Thin Fins by PSO Algorithm کمینه‌سازی میزان انتقال حرارت از محفظه های مستطیلی با جابجایی آزاد در نسبت های منظری مختلف با یافتن مشخصات آرایه‌ای ازپره های نازک عایق به وسیله الگوریتم کوچ پرندگان 295 308 944 10.22060/mej.2017.11795.5185 FA سمیرا پایان گروه مهندسی مکانیک، دانشگاه سیستان و بلوچستان، زاهدان، ایران آرمان عظیمی فر گروه مهندسی مکانیک، دانشگاه سیستان و بلوچستان، زاهدان، ایران Journal Article 2016 07 15 In the present paper, the calculation of the optimum characteristics of thin fins attached to the hot wall in closed cavities with different aspect ratios has been investigated. Free convection is predominant in the cavity. The equations of continuity, momentum, and energy are discretized by means of finite volume method and the equations will be solved by a SIMPLER algorithm. The fins are connected to the hot wall and Particle Swarm algorithm is used to optimize the location and the length of fins. In order to model fins with high heat transfer, the dimensionless diffusion coefficients of momentum and energy equations are set equal to infinity and for the modeling of insulator fins, these coefficients are considered infinite and very small, respectively. The aim is to find the optimum characteristics of the array of fins attached to the hot wall in the rectangular cavities in such a way that the heat transfer from the cold wall is minimized. The results of particle swarm optimization algorithm are compared with the reference amounts. Results show that the particle swarm optimization algorithm is capable to find the optimum characteristics of an array of fins that is not calculated by the other methods, until now. The obtained results showed that with the increase of aspect ratio, the increase of the number of fins (increase in the number of variables), the particle swarm optimization algorithm might not have the needed ability to find the general optimum. This issue was studied by some numerical tests. Therefore, it was concluded that by decreasing the number of variables (Fixed location) and finding only the length of each fin, and also by increasing the number of particles in the sample space, the accuracy of the algorithm can be increased. <span lang="AR-SA" dir="RTL">در</span><span lang="AR-SA"> <span dir="RTL">این</span> <span dir="RTL">مقاله</span> <span dir="RTL">محاسبه</span> <span dir="RTL">مشخصات</span> <span dir="RTL">بهینه</span> <span dir="RTL">پره های</span> <span dir="RTL">نازک</span> <span dir="RTL">متصل</span> <span dir="RTL">به</span> <span dir="RTL">دیوار</span> <span dir="RTL">گرم</span> <span dir="RTL">در</span> <span dir="RTL">محفظه­های</span> <span dir="RTL">بسته</span> <span dir="RTL">با</span> <span dir="RTL">جابه­جایی</span> <span dir="RTL">آزاد</span> <span dir="RTL">در</span> <span dir="RTL">نسبت­های منظری</span> <span dir="RTL">مختلف</span> <span dir="RTL">مورد</span> <span dir="RTL">بررسی</span> <span dir="RTL">قرار</span> <span dir="RTL">گرفته</span> <span dir="RTL">است</span></span><span>. <span lang="AR-SA" dir="RTL">معادلات</span><span lang="AR-SA"> <span dir="RTL">پیوستگی،</span> <span dir="RTL">ممنتوم</span> <span dir="RTL">و</span> <span dir="RTL">انرژی</span> <span dir="RTL">به وسیله</span> <span dir="RTL">روش</span> <span dir="RTL">حجم</span> <span dir="RTL">محدود،</span> <span dir="RTL">گسسته</span> <span dir="RTL">می</span> <span dir="RTL">شوند</span> <span dir="RTL">و</span> <span dir="RTL">معادلات به</span> <span dir="RTL">وسیله</span> <span dir="RTL">الگوریتم</span> <span dir="RTL">سیمپلر</span> <span dir="RTL">حل</span> <span dir="RTL">می</span> <span dir="RTL">شوند</span></span>. <span lang="AR-SA" dir="RTL">پر</span><span lang="AR-SA"> <span dir="RTL">هها</span> <span dir="RTL">روی</span> <span dir="RTL">دیوار</span> <span dir="RTL">گرم</span> <span dir="RTL">متصل</span> <span dir="RTL">می شوند</span> <span dir="RTL">و</span> <span dir="RTL">از</span> <span dir="RTL">الگوریتم</span> <span dir="RTL">بهینه</span> <span dir="RTL">سازی</span> <span dir="RTL">کوچ</span> <span dir="RTL">پرندگان</span> <span dir="RTL">برای</span> <span dir="RTL">بهین</span> <span dir="RTL">هسازی</span> <span dir="RTL">مکان</span> <span dir="RTL">و طول</span> <span dir="RTL">پره ها</span> <span dir="RTL">استفاده</span> <span dir="RTL">شده</span> <span dir="RTL">است</span></span>. <span lang="AR-SA" dir="RTL">برای</span><span lang="AR-SA"> <span dir="RTL">مدل</span> <span dir="RTL">سازی</span> <span dir="RTL">پره های</span> <span dir="RTL">با</span> <span dir="RTL">هدایت</span> <span dir="RTL">حرارتی</span> <span dir="RTL">بالا،</span> <span dir="RTL">ضرایب</span> <span dir="RTL">بدون</span> <span dir="RTL">بعد</span> <span dir="RTL">دیفیوژن</span> <span dir="RTL">معادلات</span> <span dir="RTL">ممنتوم</span> <span dir="RTL">و</span> <span dir="RTL">انرژی</span> <span dir="RTL">بی</span> <span dir="RTL">نهایت، و</span> <span dir="RTL">برای</span> <span dir="RTL">مدل</span> <span dir="RTL">سازی</span> <span dir="RTL">پره</span> <span dir="RTL">های</span> <span dir="RTL">عایق</span> <span dir="RTL">ضرایب</span> <span dir="RTL">دیفیوژن</span> <span dir="RTL">معادلات</span> <span dir="RTL">ممنتوم</span> <span dir="RTL">و</span> <span dir="RTL">انرژی</span> <span dir="RTL">به</span> <span dir="RTL">ترتیب</span> <span dir="RTL">بی نهایت</span> <span dir="RTL">و</span> <span dir="RTL">بسیار</span> <span dir="RTL">کوچک</span> <span dir="RTL">قرار</span> <span dir="RTL">داده</span> <span dir="RTL">شده</span> <span dir="RTL">است</span></span>. <span lang="AR-SA" dir="RTL">هدف، یافتن</span><span lang="AR-SA"> <span dir="RTL">مشخصات</span> <span dir="RTL">بهینه</span> <span dir="RTL">آرایه</span> <span dir="RTL">پره های</span> <span dir="RTL">متصل</span> <span dir="RTL">شده</span> <span dir="RTL">به</span> <span dir="RTL">دیوار</span> <span dir="RTL">گرم</span> <span dir="RTL">محفظه های</span> <span dir="RTL">مستطیلی</span> <span dir="RTL">است</span> <span dir="RTL">به</span> <span dir="RTL">نحوی</span> <span dir="RTL">که</span> <span dir="RTL">انتقال</span> <span dir="RTL">حرارت</span> <span dir="RTL">از</span> <span dir="RTL">دیوار</span> <span dir="RTL">سرد</span> <span dir="RTL">کمینه شود</span></span>. <span lang="AR-SA" dir="RTL">برای</span><span lang="AR-SA"> <span dir="RTL">این</span> <span dir="RTL">کار</span> <span dir="RTL">نتایج</span> <span dir="RTL">الگوریتم</span> <span dir="RTL">کوچ</span> <span dir="RTL">پرندگان</span> <span dir="RTL">با</span> <span dir="RTL">مقادیر</span> <span dir="RTL">مرجع</span> <span dir="RTL">مقایسه</span> <span dir="RTL">شده</span> <span dir="RTL">است</span></span>. <span lang="AR-SA" dir="RTL">نتایج</span><span lang="AR-SA"> <span dir="RTL">نشان</span> <span dir="RTL">می دهد</span> <span dir="RTL">که</span> <span dir="RTL">الگوریتم</span> <span dir="RTL">کوچ</span> <span dir="RTL">پرندگان</span> <span dir="RTL">قادر</span> <span dir="RTL">به پیدا</span> <span dir="RTL">کردن</span> <span dir="RTL">مشخصات</span> <span dir="RTL">بهینه</span> <span dir="RTL">آرای</span> <span dir="RTL">های</span> <span dir="RTL">از</span> <span dir="RTL">پره ها</span> <span dir="RTL">است</span> <span dir="RTL">که</span> <span dir="RTL">تا</span> <span dir="RTL">به</span> <span dir="RTL">حال</span> <span dir="RTL">با</span> <span dir="RTL">استفاده</span> <span dir="RTL">از</span> <span dir="RTL">روش های</span> <span dir="RTL">دیگر</span> <span dir="RTL">محاسبه</span> <span dir="RTL">نشده</span> <span dir="RTL">است</span></span>. <span lang="AR-SA" dir="RTL">نتایج</span><span lang="AR-SA"> <span dir="RTL">به</span> <span dir="RTL">دست</span> <span dir="RTL">آمده</span> <span dir="RTL">نشان داد</span> <span dir="RTL">که</span> <span dir="RTL">با</span> <span dir="RTL">افزایش</span> <span dir="RTL">نسبت</span> <span dir="RTL">منظری</span> <span dir="RTL">و</span> <span dir="RTL">افزایش</span> <span dir="RTL">تعداد</span> <span dir="RTL">پره</span> <span dir="RTL">ها</span></span> )<span lang="AR-SA" dir="RTL">افزایش</span><span lang="AR-SA"> <span dir="RTL">تعداد</span> <span dir="RTL">متغیرها</span></span>( <span lang="AR-SA" dir="RTL">ممکن</span><span lang="AR-SA"> <span dir="RTL">است</span> <span dir="RTL">الگوریتم</span> <span dir="RTL">کوچ</span> <span dir="RTL">پرندگان</span> <span dir="RTL">توانایی</span> <span dir="RTL">لازم</span> <span dir="RTL">جهت</span> <span dir="RTL">یافتن بهینه</span> <span dir="RTL">کلی</span> <span dir="RTL">را</span> <span dir="RTL">نداشته</span> <span dir="RTL">باشد</span></span>. <span lang="AR-SA" dir="RTL">این</span><span lang="AR-SA"> <span dir="RTL">موضوع</span> <span dir="RTL">با</span> <span dir="RTL">چند</span> <span dir="RTL">تست</span> <span dir="RTL">عددی</span> <span dir="RTL">مورد</span> <span dir="RTL">بررسی</span> <span dir="RTL">قرار</span> <span dir="RTL">گرفت</span></span>. <span lang="AR-SA" dir="RTL">به</span><span lang="AR-SA"> <span dir="RTL">این</span> <span dir="RTL">ترتیب</span> <span dir="RTL">با</span> <span dir="RTL">کاهش</span> <span dir="RTL">تعداد</span> <span dir="RTL">متغیرها</span></span> )<span lang="AR-SA" dir="RTL">ثابت</span><span lang="AR-SA"> <span dir="RTL">نگه</span> <span dir="RTL">داشتن مکان</span></span>( <span lang="AR-SA" dir="RTL">و</span><span lang="AR-SA"> <span dir="RTL">یافتن</span> <span dir="RTL">تنها</span> <span dir="RTL">طول</span> <span dir="RTL">هر</span> <span dir="RTL">یک</span> <span dir="RTL">از</span> <span dir="RTL">پره</span> <span dir="RTL">ها</span> <span dir="RTL">و</span> <span dir="RTL">همچنین</span> <span dir="RTL">افزایش</span> <span dir="RTL">تعداد</span> <span dir="RTL">ذرات</span> <span dir="RTL">در</span> <span dir="RTL">فضای</span> <span dir="RTL">نمونه</span> <span dir="RTL">مشخص</span> <span dir="RTL">شد</span> <span dir="RTL">دقت</span> <span dir="RTL">الگوریتم</span> <span dir="RTL">را</span> <span dir="RTL">می</span> <span dir="RTL">توان</span> <span dir="RTL">افزایش</span> <span dir="RTL">داد</span></span>.</span> https://mej.aut.ac.ir/article_944_64223ccf70bbb65a3a4aceac37e21016.pdf