本文關(guān)鍵詞： Rayleigh-Bénard熱對(duì)流 溫度邊界層 湍流 并行直接數(shù)值模擬　出處：《物理學(xué)報(bào)》2016年20期 　論文類型：期刊論文

【摘要】：本文采用湍流熱對(duì)流的并行直接數(shù)值模擬(PDM-DNS),計(jì)算了系列Ra數(shù)的二維方腔和三維扁方腔的Rayleigh-Bénard熱對(duì)流.針對(duì)平均場(chǎng)計(jì)算結(jié)果,選取Ra=10~9,10~(10),5×10~(10),討論了二維方腔和展向平均三維扁方腔熱對(duì)流流動(dòng)特性.發(fā)現(xiàn)二維方腔和三維扁方腔流動(dòng)中都存在大尺度環(huán)流和角渦,而且隨著Ra數(shù)的增加,大尺度環(huán)流的形狀變圓,角渦尺寸變小.在二維方腔流動(dòng)中,大尺度環(huán)流呈橢圓形,有四個(gè)角渦,而展向平均三維扁方腔流動(dòng)中,大尺度環(huán)流呈梭形,只有兩個(gè)角渦.由于角渦特性的不同,二維方腔流動(dòng)中羽流向上運(yùn)動(dòng)的范圍比展向平均三維扁方腔流動(dòng)更廣,造成二維流動(dòng)局部區(qū)域溫度分布高溫層厚度變大.溫度邊界層厚度λ_θ與Ra數(shù)之間存在標(biāo)度關(guān)系,二維方腔和三維扁方腔熱對(duì)流溫度邊界層變化的標(biāo)度指數(shù)基本一致,標(biāo)度關(guān)系的系數(shù)稍有不同.
[Abstract]:A parallel direct numerical simulation of turbulent thermal convection (PDM-DNS) is presented in this paper. The Rayleigh-B 茅 nard thermal convection of two-dimensional square cavity and three-dimensional flat square cavity with a series of Ra numbers are calculated. The thermal convection flow characteristics of two-dimensional square cavity and spanwise average three-dimensional flat square cavity are discussed. It is found that there are large scale circulation and angular vortex in two-dimensional square cavity and three-dimensional flat square cavity flow. With the increase of Ra number, the shape of large scale circulation becomes round and the size of angular vortex becomes smaller. In two-dimensional square cavity flow, the large scale circulation is elliptical, with four angular vortices, while in the spanned average three dimensional flat square cavity flow. The large scale circulation is fusiform with only two angular vortices. Due to the different characteristics of angular vortices, the upward movement of plume in two-dimensional square cavity flow is wider than that in spanwise average three-dimensional flat square cavity. As a result, the thickness of the high temperature layer increases in the local temperature distribution of two-dimensional flow, and there is a scaling relationship between the thickness of the temperature boundary layer 位 _ 胃 and the Ra number. The scalar exponents of the boundary layer variation of the thermal convection temperature in two dimensional square cavity and three dimensional flat square cavity are basically the same, and the coefficient of scaling relation is slightly different.
【作者單位】： 中山大學(xué)力學(xué)系;
【基金】：國(guó)家自然科學(xué)基金(批準(zhǔn)號(hào):11372362,11452002) 中央高校基本科研業(yè)務(wù)費(fèi)(批準(zhǔn)號(hào):14lgjc02) 國(guó)家自然科學(xué)基金委員會(huì)-廣東省人民政府聯(lián)合基金(第二期)超級(jí)計(jì)算科學(xué)應(yīng)用研究專項(xiàng)(批準(zhǔn)號(hào):nsfc2015_570)資助的課題~~
【分類號(hào)】：O357.5
【正文快照】： 1引言 熱對(duì)流現(xiàn)象是自然界運(yùn)動(dòng)中的基本物理現(xiàn)象,它廣泛存在于天體、太陽(yáng)、地球地幔、大氣環(huán)流和海洋環(huán)流等自然界中,以及核反應(yīng)堆堆芯冷卻系統(tǒng)、化工產(chǎn)品生產(chǎn)和電子元件設(shè)計(jì)等工程應(yīng)用領(lǐng)域中.湍流熱對(duì)流物理和流動(dòng)特性的研究可以深化認(rèn)識(shí)自然界中的對(duì)流現(xiàn)象,也可以對(duì)解決工

【相似文獻(xiàn)】

相關(guān)期刊論文 前4條

1 李國(guó)鈞,黃莉;自然對(duì)流溫度邊界層的數(shù)值解[J];華中理工大學(xué)學(xué)報(bào);1992年02期

2 張浩;張欣欣;鄭連存;;冪律流體溫度邊界層定性分析和數(shù)值模擬[J];工程熱物理學(xué)報(bào);2008年06期

3 張贊牢;唐曉寅;王建華;黃磊;;管道熱邊界層方程的迎風(fēng)有限元分析[J];后勤工程學(xué)院學(xué)報(bào);2007年02期

4 ;[J];;年期

相關(guān)碩士學(xué)位論文 前2條

1 呂小亮;背景紋影技術(shù)的溫度場(chǎng)測(cè)量[D];浙江大學(xué);2011年

2 薛元;細(xì)顆粒在流動(dòng)與溫度邊界層中的運(yùn)動(dòng)規(guī)律研究[D];清華大學(xué);2002年

，

本文編號(hào)：1456018