本文選題：吸葉機 + CFD��； 參考：《東南大學(xué)》2015年碩士論文

【摘要】：吹吸一體式吸葉機工作時,噪聲很大,操作舒適性能較差,嚴(yán)重危害操作者人體健康。目前有關(guān)降低吸葉機工作噪聲的研究很少,大部分企業(yè)在吸葉機設(shè)計過程中依賴經(jīng)驗,采用仿制和實驗的方法,成本高,研發(fā)效率低。本文將CFD(Computational Fluid Dynamics)仿真技術(shù)融入到吹吸一體式吸葉機優(yōu)化設(shè)計中,以提高吸葉機氣動性能和降低工作噪聲為目的,對吸葉機工作部件和流道進行優(yōu)化。首先,對吸葉機結(jié)構(gòu)進行分析,確定需要優(yōu)化的5個具體工作指標(biāo)：吸葉時入口流量和入口靜壓、吹葉時出口流量、吹/吸狀態(tài)噪聲聲壓級。簡化吸葉機部分次要結(jié)構(gòu),抽取吸葉機流道,通過合理的網(wǎng)格劃分方式和求解條件獲得吸葉機在吹葉和吸葉狀態(tài)下的仿真模型,完成吸葉機的穩(wěn)態(tài)流場仿真。在蝸殼出口處,由于設(shè)計不合理,產(chǎn)生渦旋,導(dǎo)致流動損失和噪聲增大。平直蝸舌未能起到很好的導(dǎo)流作用,吹葉時,蝸舌附近處有空氣回流。流場仿真的結(jié)果為結(jié)構(gòu)優(yōu)化設(shè)計提供參考。其次,為了提高計算精度,同時考慮到計算機性能,通過大渦模型與FW-H聲模型結(jié)合的方法,計算吸葉機吹/吸狀態(tài)下監(jiān)測點處噪聲。旋轉(zhuǎn)噪聲基頻及倍頻所在頻帶的噪聲明顯大于其他頻段噪聲,因此吸葉機氣動噪聲以旋轉(zhuǎn)噪聲為主。再次,按照風(fēng)機氣動性能和噪聲測量標(biāo)準(zhǔn),測量吸葉機吹葉時出口流量,吸葉時入口流量和靜壓,以及監(jiān)測點處噪聲聲壓級,分析采集的噪聲信號和振動信號。將實驗結(jié)果與仿真結(jié)果進行對比,驗證了模型的正確性。最后,以葉片數(shù)、輪轂比和出口安裝角為優(yōu)化因素,采用正交試驗法對葉輪進行結(jié)構(gòu)優(yōu)化。針對蝸殼結(jié)構(gòu)的不合理,在蝸殼出口采用圓弧連接方式,用圓弧蝸舌替換平直蝸舌,減輕了氣流對壁面的沖擊；推拉式吹/吸轉(zhuǎn)換裝置減少了氣流泄露,氣動性能得到提高。當(dāng)圓弧蝸舌半徑為4.3mm時,氣動性能和噪聲達到最佳平衡點。依據(jù)相似定律,將轉(zhuǎn)速降低2000rpm。最終吸葉機吹葉和吸葉時噪聲明顯降低,同時氣動性能得到提高,很好地達到了優(yōu)化目標(biāo)。
[Abstract]:When the suction blower is working, the noise is great, the operating comfort is poor, and the operator's health is badly damaged. At present, there are few researches on reducing the working noise of the suction machine. Most enterprises rely on experience in the design process of the suction blye machine, using the method of imitation and experiment, the cost is high, and the R & D efficiency is low. This paper will be CFD (Computational). Fluid Dynamics) simulation technology is integrated into the optimization design of the blower suction blower. In order to improve the aerodynamic performance of the suction blower and reduce the working noise, the working parts and channel of the suction blower are optimized. First, the structure of the suction blower is analyzed, and 5 specific working indexes are determined: the inlet flow and entrance when the blade is sucked. Static pressure, outlet flow and sound pressure level of blowing / suction state. Simplify part of the secondary structure of the suction blower, extract the flow path of the suction blower, obtain the simulation model of the blade under the state of blower and leaf suction through reasonable grid division and solving conditions, and complete the simulation of the steady flow field of the suction blower. At the outlet of the worm shell, the design is unreasonable, The flow loss and noise increase. The straight worm tongue can not play a good diversion effect. When the blade is blown, the air flow is reflux near the worm tongue. The result of the simulation of the flow field provides a reference for the structural optimization design. Secondly, in order to improve the calculation accuracy and the computer performance, the combination of the large eddy model and the FW-H sound model is taken into consideration. The method is to calculate the noise at the monitoring point in the state of the blower blowing / suction. The noise of the fundamental frequency of the rotating noise and the frequency of the frequency doubling is obviously greater than that of the other frequency bands. Therefore, the aerodynamic noise of the suction blower is dominated by the rotating noise. Again, according to the pneumatic performance and noise measurement standard of the fan, the flow rate of the blade when the blade is blown and the inlet flow and static time of the blade are measured. Pressure, noise sound pressure level at the monitoring point, analysis of the noise and vibration signals collected. Comparing the experimental results with the simulation results, the correctness of the model is verified. Finally, the optimization factors are the number of blades, the hub ratio and the outlet installation angle, and the orthogonal test method is used to optimize the structure of the blade wheel. The outlet of the volute adopts a circular arc connection, replacing the straight worm tongue with a circular spiral tongue, reducing the impact of the air flow on the wall, and reducing the air leakage and improving the aerodynamic performance. When the radius of the circular spiral tongue is 4.3mm, the aerodynamic performance and noise reach the best balance point. The speed is reduced by 2000rpm according to the similarity law. Finally, the noise of the suction machine is obviously reduced when the blade is blown and the leaves are sucked, and the aerodynamic performance is improved.
【學(xué)位授予單位】：東南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TU986.32

【相似文獻】

相關(guān)重要報紙文章 前1條

1 記者 蔣中意　通訊員 舒清海;武義周一機電攬到上海世博會訂單[N];金華日報;2009年

相關(guān)碩士學(xué)位論文 前1條

1 陶松洋;吹吸一體式吸葉機CFD仿真與降噪研究[D];東南大學(xué);2015年

，

本文編號：1999995