本文選題：公路隧道 + 阻力格柵��； 參考：《長安大學(xué)》2015年碩士論文

【摘要】：隧道通風(fēng)物理模型試驗中,由于試驗場地和試驗條件的限制,通常難以建立1:1比例模型或同比尺縮小模型�？紤]到通風(fēng)模型試驗往往是對局部復(fù)雜部位進行研究,在保證原型與模型阻力相似的前提下,采用變率模型可以有效縮短隧道通風(fēng)模型長度。在隧道模型試驗中設(shè)置阻力格柵缺少系統(tǒng)的理論支持,同時如何選取和設(shè)置阻力格柵值得研究。基于以上問題,本文針對阻力格柵進行了深入研究。1.介紹了隧道通風(fēng)物理模型試驗的相似準則和自模區(qū)理論,以此為基礎(chǔ),闡述了阻力格柵的等效作用原理及作用分類,推導(dǎo)出了阻力格柵局部阻力損失系數(shù)ξ的計算公式以及阻力格柵等效模型長度Lm的計算公式,并闡述了阻力格柵模型的適用性。2.采用計算流體力學(xué)軟件Fluent對不同孔數(shù)的阻力格柵流場進行模擬研究,研究結(jié)果表明,當有效面積比一定時,阻力格柵的孔數(shù)越多,其均流作用越顯著,風(fēng)流波動逐漸降低,上下游影響長度顯著減小。阻力格柵孔數(shù)大于500時,其上下游影響總長度小于3倍模型當量直徑。3.通過物理模型試驗研究阻力格柵串聯(lián)間距、串聯(lián)數(shù)量的影響以及阻力損失系數(shù),為阻力格柵的選取和設(shè)置提供指導(dǎo)建議,同時介紹阻力格柵在隧道通風(fēng)模型試驗中的具體應(yīng)用。試驗結(jié)果表明,模型加入阻力格柵后,仍然存在自模區(qū),其臨界風(fēng)速與模型的臨界風(fēng)速近乎相等;阻力格柵的串聯(lián)間距、組數(shù)、規(guī)格對模型進入自模區(qū)的臨界風(fēng)速幾乎沒有影響;每組格柵局部阻力損失系數(shù)隨格柵組數(shù)的增多而降低,降低的速率隨著格柵組數(shù)的增多而減小;阻力格柵串聯(lián)間距應(yīng)不小于三倍模型當量直徑。
[Abstract]:In the physical model test of tunnel ventilation, due to the limitation of test site and test conditions, it is usually difficult to establish the 1:1 scale model or the scale reduction model. Considering that the ventilation model test is usually to study the local complex parts, the model length of tunnel ventilation can be effectively shortened by using the variable rate model on the premise that the prototype is similar to the model resistance. It is necessary to study how to select and set resistance grille in tunnel model test, which lacks the theoretical support of the system. Based on the above problems, the resistive grille is studied in this paper. This paper introduces the similarity criterion and self-model zone theory of physical model test of tunnel ventilation. Based on this, the equivalent action principle and action classification of resistance grille are expounded. The formula of local resistance loss coefficient 尉 and the length of resistance grid equivalent model L m are derived, and the applicability of resistance grid model is expounded. The flow field of resistance grille with different number of holes is simulated by fluent. The results show that when the effective area ratio is fixed, the more the number of holes in resistance grille is, the more the average flow is, and the fluctuation of wind flow decreases gradually. The influence length of upstream and downstream decreases significantly. When the number of resistance grille holes is greater than 500, the total length of the upstream and downstream influences is less than 3 times the equivalent diameter of the model. Through the physical model test, the influence of the series distance, the number of series and the coefficient of resistance loss of the resistance grille are studied, which provides guidance suggestions for the selection and setting of the resistance grille. At the same time, the application of the resistance grille in the tunnel ventilation model test is introduced. The experimental results show that the self-mode region still exists after the resistance grille is added to the model, and the critical wind speed is almost equal to the critical wind speed of the model. The local drag loss coefficient of each grid decreases with the increase of the number of grid groups, and the decreasing rate decreases with the increase of the number of grid groups. The resistance grid in series should not be less than three times the equivalent diameter of the model.
【學(xué)位授予單位】：長安大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U453.5

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相關(guān)期刊論文 前1條

1 方磊,謝永利,李寧軍;公路隧道豎井送排式通風(fēng)排風(fēng)口角度優(yōu)化模型試驗研究[J];現(xiàn)代隧道技術(shù);2005年05期

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本文編號：2117409