本文選題：PIV + LES��； 參考：《北京化工大學(xué)》2015年碩士論文

【摘要】：目前國(guó)內(nèi)外的研究越來(lái)越多的集中在過(guò)程強(qiáng)化以及新型反應(yīng)裝置的設(shè)計(jì)上面,其中限定式撞擊流反應(yīng)器(CIJRs)能夠?yàn)榉磻?yīng)體系提供優(yōu)良的傳遞特性和混合效果,撞擊流已廣泛的應(yīng)用于燃燒,吸收,干燥,解析,萃取以及納米制備等工業(yè)生產(chǎn)中,然而流體在非對(duì)稱CIJRs內(nèi)的流動(dòng)特性還沒(méi)有得到充分的研究,尤其高Re體系。本實(shí)驗(yàn)主要研究非對(duì)稱(3-4 mm)反應(yīng)器在不同流速下(Re=17596-45309)的流動(dòng)特性,通過(guò)2DPIV技術(shù)獲取平均速度分布、湍動(dòng)能分布、駐點(diǎn)偏移規(guī)律等。在各向同性的假設(shè)下,湍動(dòng)能的計(jì)算利用兩個(gè)方向的速度進(jìn)行計(jì)算,通過(guò)PIV實(shí)驗(yàn)與LES模擬的對(duì)比驗(yàn)證了模擬的可靠性�；趯�(shí)驗(yàn)與模擬的結(jié)果,研究表明：瞬態(tài)流場(chǎng)和駐點(diǎn)位置每時(shí)每刻都在一定的范圍內(nèi)波動(dòng),而且實(shí)驗(yàn)與模擬的駐點(diǎn)位置分布均滿足正態(tài)分布,實(shí)驗(yàn)駐點(diǎn)位置波動(dòng)范圍較模擬偏大,這與脈動(dòng)速度在入口處偏大這一顯現(xiàn)是相一致；在Re=17000-45000之間,只要保證入口充分的發(fā)展?fàn)顟B(tài),恒定的Re比,Re大小對(duì)流體的平均速度U,V,W分布、脈動(dòng)速度分布和湍動(dòng)能速度分布影響不大；在只改變軸線上方空間H的條件下,較大的上方空間更有利于增強(qiáng)傳遞的效果,較低的上方空間對(duì)駐點(diǎn)位置偏移的影響顯著；在只考慮速度比影響的條件下,流速比對(duì)無(wú)因次的駐點(diǎn)位置偏移影響顯著,10%的流速比的波動(dòng)將會(huì)造成35%駐點(diǎn)偏移量,在反應(yīng)器的中間位置流體的混合效果最好,因此有必要確保兩流體入口流速比以保證流體相撞在反應(yīng)器的中間位置,這些針對(duì)撞擊流流動(dòng)特性的研究為將來(lái)反應(yīng)器的設(shè)計(jì)以及裝置優(yōu)化提供了基礎(chǔ)的數(shù)據(jù)。
[Abstract]:At present, more and more researches at home and abroad focus on process strengthening and the design of new reaction equipment, in which the limited impinging flow reactor CIJRs can provide excellent transfer characteristics and mixing effect for the reaction system. Impingement flow has been widely used in combustion, absorption, drying, desorption, extraction and nanocrystalline preparation. However, the flow characteristics of the fluid in asymmetric CIJRs have not been fully studied, especially in the high re system. In this experiment, the flow characteristics of an asymmetric reactor at different velocities were studied. The average velocity distribution, turbulent kinetic energy distribution and stationary point migration were obtained by 2DPIV technique. Under the assumption of isotropy, the turbulent kinetic energy is calculated by two directions of velocity, and the reliability of the simulation is verified by comparing the PIV experiment with the LES simulation. Based on the experimental and simulation results, it is shown that the transient flow field and the stationary point position fluctuate in a certain range at every moment, and the distribution of the experimental and simulated stationary point positions satisfies the normal distribution. The fluctuating range of the experimental stationary point is larger than that of the simulation, which is consistent with the phenomenon that the pulsation velocity is larger at the entrance, and between the Re=17000-45000, the constant re ratio to the average velocity of the fluid is U / V / W distribution, as long as the sufficient development state of the inlet is ensured, and the constant re ratio is larger than the re ratio to the average velocity of the fluid. Under the condition of only changing the space H above the axis, the larger upper space is more favorable to enhance the transfer effect, and the lower upper space has a significant effect on the migration of the stationary point. Under the condition of considering only the effect of velocity ratio, the fluctuation of velocity ratio of 10% to 10% will result in 35% migration of stationary point, and the mixing effect of fluid in the middle of the reactor is the best. Therefore, it is necessary to ensure the inlet velocity ratio of the two fluids to ensure the collision position of the fluid in the middle of the reactor. These studies on the impinging flow characteristics provide the basic data for the design of the reactor and the device optimization in the future.
【學(xué)位授予單位】：北京化工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TQ021.1

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本文編號(hào)：1865057