روشهای عددی در مهندسی

روشهای عددی در مهندسی

حل عددی جریان آشفته در یک سیستم خودخنک‌کن جدید غیرفعال

نوع مقاله : مقاله پژوهشی

نویسندگان
1 دانشکده نفت و گاز گچساران، دانشگاه یاسوج، گچساران، ایران
2 دانشکده مهندسی مکانیک، دانشگاه صنعتی اصفهان، اصفهان، ایران
چکیده
در این مطالعه، یک قطعه مستطیلی شکل با تولید حرارت داخلی مورد بررسی قرار گرفته‌است. برای خنک‌سازی این قطعه، کانال‌های موازی درون آن تعبیه شده‌اند. بخشی از این کانال‌ها به‌عنوان کانال‌های فعال (دارای جریان سیال خنک‌کننده) و بخش دیگر به‌عنوان کانال‌های غیرفعال (حاوی سیال ساکن) عمل می‌کنند. این کانال‌ها توسط میکروترموستات‌های گرمایی به یکدیگر متصل شده‌اند. با افزایش شار حرارتی در نواحی مختلف قطعه، کانال‌های غیرفعال در همان ناحیه به کانال‌های فعال تبدیل می‌شوند و در نتیجه خنک‌کاری در مناطق با شار حرارتی بالا بهبود یافته و دمای کلی قطعه کاهش می‌یابد. در این پژوهش، جریان سیال به‌صورت دائمی و آشفته در نظر گرفته شده‌است. نتایج نشان می‌دهند که عملکرد خنک‌کنندگی در نقاط فعال‌سازی ترموستات‌ها، به‌ویژه در نزدیکی ورودی کانال‌ها، مؤثرتر بوده و با افزایش شار حرارتی، بهبود می‌یابد. بیشترین اختلاف دمای ماکزیمم، 56 درجه سانتیگراد در جریان آشفته و در فاصله 200 میلی‌متری از ابتدای کانال دوم مشاهده شده ‌است. در این حالت، ترموستات‌ها مسیر بین کانال‌های فعال و غیرفعال را باز کرده‌اند. بهینه‌سازی سیستم خودخنک‌کن غیرفعال پیشنهادی نشان می‌دهد که این روش منجر به حداکثر انتقال حرارت و کاهش دمای قطعه می‌شود. همچنین، موقعیت ترموستات‌ها نسبت به محل اعمال شار حرارتی ماکزیمم تأثیر قابل‌توجهی در عملکرد خنک‌کاری دارد. در صورتی که بازشدگی ترموستات‌ها قبل از ناحیه با شار حرارتی ماکزیمم اتفاق بیفتد، دمای ماکزیمم قطعه به‌صورت چشمگیری کاهش می‌یابد. علاوه‌براین، با کاهش ضریب هدایت حرارتی قطعه، استفاده از سیستم خودخنک‌کن غیرفعال جدید موجب کاهش بیشتر دمای ماکزیمم می‌شود.
کلیدواژه‌ها
موضوعات

عنوان مقاله English

Numerical Simulation of Turbulent Flow in a Novel Passive Self-Cooling System

نویسندگان English

seyedehzahra sajadi 1
mohamadreza salimpour 2
1 Department of Mechanical Engineering, Faculty of Oil and Gas Gachsaran, Yasuj, Iran
2 Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran
چکیده English

In this study, a rectangular component with internal heat generation is considered, which incorporates parallel cooling channels. Some of these channels are active (containing flowing coolant fluid), while others are passive (containing stagnant fluid). The active and passive channels are interconnected through micro thermal switches. When heat flux increases in a specific region of the component, the passive channels in that region convert to active channels, thereby enhancing cooling in high heat-flux areas and reducing the components’ temperature. The fluid flow in this research is assumed to be steady and turbulent. Results demonstrate that cooling is more effective near the channel inlets where thermal switches activate, with cooling performance improving as heat flux increases. The maximum observed temperature difference in turbulent flow was 56°C, occurring when thermal switches opened the pathway between active and passive channels at 200 mm from the inlet of the second channel. The proposed novel self-regulating passive cooling system was evaluated, with calculations confirming optimal heat transfer and cooling performance in this configuration. The positioning of thermal switches relative to the maximum heat flux application zone significantly impacts cooling effectiveness. When switches open before the peak heat flux region, maximum component temperature is substantially reduced. Additionally, components with lower thermal conductivity exhibit greater reductions in peak temperature when utilizing this new passive cooling system.

کلیدواژه‌ها English

Self-cooling
Electronic components
Heat flux
Microchannel
Passive
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