本文選題：防風(fēng)網(wǎng)　切入點(diǎn)：阻力系數(shù)　出處：《青島科技大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：防風(fēng)網(wǎng)抑塵工程技術(shù)是防治大型露天料堆場(chǎng)二次揚(yáng)塵的有效措施,其核心部件為防風(fēng)網(wǎng),而有關(guān)防風(fēng)網(wǎng)的受力計(jì)算目前尚未形成專門的規(guī)范,此值直接關(guān)系到鋼構(gòu)架的結(jié)構(gòu)設(shè)計(jì),對(duì)于工程建設(shè)具有重要的指導(dǎo)意義。本文利用FLUENT軟件進(jìn)行不同開孔率對(duì)平面型、蝶形防風(fēng)網(wǎng)尾流區(qū)內(nèi)流場(chǎng)特性影響的數(shù)值模擬,并與PIV實(shí)驗(yàn)數(shù)據(jù)的相比較,驗(yàn)證了數(shù)值模型的合理性與正確性。在此基礎(chǔ)上,開展了來流風(fēng)速、開孔率和開孔直徑對(duì)平面型、蝶形防風(fēng)網(wǎng)受力影響的數(shù)值模擬。研究結(jié)果表明:(1)平面型、蝶形防風(fēng)網(wǎng)的阻力系數(shù)隨著來流風(fēng)速增加逐漸減小,而當(dāng)來流風(fēng)速大于10.0m/s時(shí),它們的阻力系數(shù)基本不隨來流風(fēng)速的增加而變化,考慮到防風(fēng)網(wǎng)工程建設(shè)中,來流風(fēng)速的選取一般是基于當(dāng)?shù)?0年內(nèi)的最大風(fēng)速,其值通常大于10.0m/s。因此,忽略來流風(fēng)速的變化對(duì)阻力系數(shù)的影響;(2)當(dāng)來流風(fēng)速和開孔直徑不變時(shí),平面型防風(fēng)網(wǎng)的阻力系數(shù)隨開孔率的增加呈指數(shù)減小的趨勢(shì),其擬合公式:當(dāng)d=6mm,0＜(?)≤0.353時(shí),cd=2.342(1-(?)2.652);當(dāng)來流風(fēng)速和開孔率不變時(shí),平面型防風(fēng)網(wǎng)的阻力系數(shù)隨開孔直徑的增加呈非線性減小的趨勢(shì),其擬合公式:當(dāng)4mm≤d≤12mm時(shí),cd((?)=0.264)=2.838-0.171d+0.0156d2- 0.00048d3;(3)蝶形防風(fēng)網(wǎng)縱向間距對(duì)阻力系數(shù)的影響與開孔率有關(guān),在較小開孔率時(shí),縱向間距對(duì)阻力系數(shù)的影響小于開孔直徑對(duì)阻力系數(shù)的影響,而在較大開孔率時(shí),縱向間距對(duì)阻力系數(shù)的影響大于開孔直徑對(duì)阻力系數(shù)的影響;橫向間距對(duì)阻力系數(shù)的影響小于開孔直徑對(duì)阻力系數(shù)的影響;(4)出于減小蝶形防風(fēng)網(wǎng)受力考慮,在相同網(wǎng)孔排列形式和開孔率的情況下,優(yōu)選開孔直徑較大的蝶形防風(fēng)網(wǎng);(5)通過對(duì)數(shù)值結(jié)果進(jìn)行擬合方程得到蝶形防風(fēng)網(wǎng)阻力系數(shù)的計(jì)算式:當(dāng)6.6mm≤d≤9.5mm,0＜(?)≤0.367時(shí)cd=k(?)+2.280其中k=0.00185-0.030d-0.0067d2
[Abstract]:The anti-dust engineering technology of windproof net is an effective measure to prevent and cure the secondary hoisting dust in large open-air material storage yard. Its core component is the wind-proof net, but the force calculation of the wind-proof net has not yet formed a special specification. This value is directly related to the structural design of the steel frame and has important guiding significance for engineering construction. In this paper, the numerical simulation of the influence of different opening rates on the characteristics of flow field in the wake zone of plane and butterfly windbreakers is carried out by using FLUENT software. Compared with the experimental data of PIV, the rationality and correctness of the numerical model are verified. Numerical simulation of the force effect of butterfly windbreak network. The results show that the drag coefficient of butterfly windbreak network decreases gradually with the increase of incoming wind speed, and when the incoming wind speed is greater than 10.0 m / s, the resistance coefficient of butterfly windbreak network decreases gradually with the increase of incoming wind speed, and when the wind speed is greater than 10.0 m / s, Their drag coefficient basically does not change with the increase of wind speed. Considering that in the construction of windbreak network, the selection of wind speed is usually based on the maximum local wind speed in 50 years, and its value is usually greater than 10.0 m / s. Ignore the effect of the change of the wind speed on the drag coefficient. When the wind speed and the diameter of the orifice are invariant, the resistance coefficient of the planar windscreen decreases exponentially with the increase of the opening rate. The fitting formula is as follows: when the inlet velocity and the diameter of the hole are not changed, the resistance coefficient of the planar windbreak mesh decreases exponentially. ) 鈮，

本文編號(hào)：1576002