本文選題：土壤風蝕　切入點：集沙儀　出處：《內(nèi)蒙古農(nóng)業(yè)大學》2016年博士論文　論文類型：學位論文

【摘要】：開展土壤風蝕研究必須借助于先進的研究手段與方法,以獲得大量而精確的風蝕數(shù)據(jù)。集沙儀能夠采集土壤風蝕過程中隨風搬運的可蝕性顆粒,是觀測風沙流結(jié)構(gòu)和研究風沙運動規(guī)律的關(guān)鍵設(shè)備,對研究風沙運動的物理機制,揭示土壤風蝕的發(fā)生、發(fā)展和演化規(guī)律,有效防治土壤風蝕具有十分重要的作用。隨著自動控制技術(shù)的廣泛應(yīng)用,研制具有較高測量精度和較高集沙效率的新型自動集沙儀,提高觀測數(shù)據(jù)的連續(xù)性、科學性和可靠性,滿足復雜多變的野外風蝕觀測需求,成為相關(guān)研究領(lǐng)域重點內(nèi)容。針對自動集沙儀存在的因強風風力對稱重傳感器產(chǎn)生沖擊而影響測試數(shù)據(jù)的精確性以及風沙在集沙儀內(nèi)部的高效分離等問題,提出氣流分流對沖與多級擴容組合以大幅降低集沙儀內(nèi)氣流速度的思路,采用理論分析、數(shù)值模擬、試驗分析等方法,在研究利用分流對沖降速原理設(shè)計的初期風沙分離器的基礎(chǔ)上,對分流對沖與多級擴容組合式集沙儀及其內(nèi)流場特性進行研究。建立風沙分離器物理模型,分析氣流降速、氣固分離與內(nèi)流場特性的關(guān)系,探究氣流的能量損失規(guī)律和影響集沙效率的主要原因,揭示分流對沖與多級擴容組合降速機理,設(shè)計單通道采集數(shù)據(jù)的分流對沖與多級擴容組合式自動集沙儀,并測試其性能指標,為開發(fā)多通道采集數(shù)據(jù)、集沙效率更高的自動集沙儀提供理論與技術(shù)依據(jù)。研究主要結(jié)論如下：(1)利用氣流分流對沖降速原理,設(shè)計了集沙儀的關(guān)鍵部件—初期風沙分離器。試驗表明,排沙口氣流的降速幅度為86.42%,可減緩排沙口氣流對集沙盒下稱重傳感器的擾動；排氣管氣流的降速幅度為88.17%,可收集粒徑大于0.032mm的土壤顆粒,進氣口的等動力性為92.03%,基本符合等動力性要求；風速為9-18m/s時的平均集沙效率為89.6%。(2)依據(jù)管道的擴張降速理論,提出氣流分流對沖與多級擴容組合降速法,設(shè)計了改進型風沙分離器。試驗表明,排沙口氣流的降速幅度為93.45%,排氣管氣流的降速幅度為89.98%,可收集粒徑大于0.024mm的土壤顆粒,進氣口的等動力性為94.74%,平均集沙效率為91.25%。(3)湍動能場內(nèi)分布著大量的脈動氣流,脈動氣流從時均流中提取了較多的、易耗散的能量,是氣流能量損失的主要組成部分；改進型風沙分離器內(nèi)氣流能量的大量損失和速度的大幅度降低歸因于湍動能場的形成。(4)當風速、土壤粒徑分布、采集時間等一定時,對于具有較高氣固分離效率的改進型風沙分離器,若要進一步提高集沙效率,關(guān)鍵是提高其進氣口的土樣采集效率。(5)分流對沖與多級擴容組合式自動集沙儀具備了抗強風干擾性能,可實時、連續(xù)和遠距離無線采集數(shù)據(jù),自由旋轉(zhuǎn)的起動風速為4.23m/s,平均集沙效率為90.42%,數(shù)據(jù)自動采集與無線傳輸系統(tǒng)的供電續(xù)航能力達31小時以上,無障礙時信號傳輸距離為208.51m,可滿足土壤風蝕量的自動觀測需求。
[Abstract]:Research on soil wind erosion must be carried out by advanced means and methods to obtain large and accurate wind erosion data. Sand collector can collect erodible particles transported with wind in the process of soil wind erosion. It is the key equipment to observe the structure of aeolian sand flow and to study the regularity of aeolian sand movement, to study the physical mechanism of aeolian sand movement and to reveal the law of occurrence, development and evolution of soil wind erosion. With the wide application of automatic control technology, a new type of automatic sand collector with higher measurement precision and higher efficiency of Gao Ji sand is developed to improve the continuity, scientificalness and reliability of observation data. To meet the needs of complex and changeable field wind erosion observation, It has become an important research area in the related fields. Aiming at the problem that the impact of the symmetrical heavy sensor of strong wind wind on the accuracy of test data and the high efficiency separation of sand in the sand collector, the automatic sand collector has some problems, such as the impact of the strong wind wind symmetric heavy sensor, and so on. In order to reduce the airflow velocity in the sand collector, the method of theoretical analysis, numerical simulation, experimental analysis and so on is put forward. Based on the study of the initial wind-sand separator designed by using the principle of shunt hedging and deceleration, the characteristics of the combined sand collector and its internal flow field are studied. The physical model of the wind-sand separator is established, and the airflow deceleration is analyzed. The relationship between gas-solid separation and the characteristics of internal flow field, the law of energy loss of air flow and the main reasons of affecting the efficiency of sand collection are discussed, and the mechanism of velocity reduction of the combination of shunt hedging and multistage expansion is revealed. In order to develop multi-channel data collection, a single channel automatic sand collecting instrument is designed, which is composed of shunt hedge and multistage expansion, and its performance index is tested. The main conclusions are as follows: (1) the key component of the sand collector, the primary wind-sand separator, has been designed by using the principle of flow separation, hedging and deceleration. The experimental results show that, The velocity drop range of the outlet airflow is 86.42, which can slow down the disturbance of the sand outlet airflow to the weighing sensor under sandboxie, and the velocity drop range of the exhaust pipe airflow is 88.17, which can collect soil particles with diameter larger than 0.032mm. The isodynamic property of the inlet is 92.03, which basically conforms to the requirement of isodynamic property, and the average sand collection efficiency when the wind speed is 9-18m/s is 89.60.2.According to the expansion and deceleration theory of the pipeline, the combined velocity reduction method of gas flow shunt and multistage expansion and capacity reduction is put forward. An improved wind-sand separator was designed. The test results show that the velocity reduction range of the outlet flow is 93.45 and that of the exhaust pipe is 89.98. The soil particles with diameter larger than 0.024mm can be collected. The isodynamic property of the inlet is 94.74 and the average sand collection efficiency is 91.25. 3) a large number of pulsating airflows are distributed in the turbulent kinetic energy field, and a large number of dissipative energy is extracted from the time-averaged flow, which is the main component of the energy loss of the airflow. The great loss of air energy and the decrease of velocity in the improved wind-sand separator are attributed to the formation of turbulent kinetic energy field. (4) when the wind speed, soil particle size distribution, collection time, etc., are fixed, For the improved wind-sand separator with higher gas-solid separation efficiency, if the sand collection efficiency is to be further improved, The key is to improve the collection efficiency of soil sample at its inlet. (5) the automatic sand collecting instrument combined with diffluence hedge and multistage expansion has the capability of resisting strong wind interference, and can collect data in real time, continuously and remotely. The starting wind speed of free rotation is 4.23 m / s, the average sand collection efficiency is 90.422.The power supply capacity of automatic data acquisition and wireless transmission system is more than 31 hours, and the signal transmission distance is 208.51 m when there is no obstacle, which can meet the demand of automatic observation of soil wind erosion.
【學位授予單位】：內(nèi)蒙古農(nóng)業(yè)大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：S237;S157.1

【參考文獻】

相關(guān)期刊論文 前10條

1 劉海洋;孔麗麗;陳智;宣傳忠;宋濤;司志民;;可移動微型低速風洞的設(shè)計與試驗[J];農(nóng)機化研究;2016年09期

2 宋濤;陳智;麻乾;司志民;劉海洋;宣傳忠;;分流對沖式集沙儀設(shè)計與性能試驗[J];農(nóng)業(yè)機械學報;2015年09期

3 張正Pr;董治寶;;降塵收集方法對降塵效率的影響[J];環(huán)境科學;2013年02期

4 楊友勝;張建平;聶松林;;水射流噴嘴能量損失研究[J];機械工程學報;2013年02期

5 李熒;史永革;蔣富強;葛盛昌;張小勇;;全風向梯度集沙儀的研制[J];鐵道技術(shù)監(jiān)督;2012年02期

6 安磊;黃寧;;流場中集沙儀集沙效率的數(shù)值模擬[J];中國沙漠;2011年03期

7 王振波;馬藝;金有海;;切流式旋流器內(nèi)兩相流場的模擬[J];中國石油大學學報(自然科學版);2010年04期

8 趙滿全;王金蓮;劉漢濤;陳智;;集沙儀結(jié)構(gòu)參數(shù)對集沙效率的影響[J];農(nóng)業(yè)工程學報;2010年03期

9 鄒春霞;申向東;李彰俊;;陰山北麓農(nóng)牧交錯帶裸露耕地土壤風蝕物垂直分布規(guī)律[J];農(nóng)業(yè)工程學報;2010年01期

10 付麗宏;趙滿全;;旋風分離式集沙儀設(shè)計與試驗研究[J];農(nóng)機化研究;2007年10期

相關(guān)博士學位論文 前8條

1 吳翠平;SLG型粉體表面改性機流場特性與數(shù)值模擬研究[D];中國礦業(yè)大學（北京）;2013年

2 林志敏;扭帶及渦產(chǎn)生器在管內(nèi)誘導的二次流強度及其強化傳熱特性研究[D];蘭州交通大學;2011年

3 劉漢濤;陰山北麓保護性耕作地表抗風蝕效果的試驗研究[D];內(nèi)蒙古農(nóng)業(yè)大學;2006年

4 陳智;陰山北麓農(nóng)牧交錯區(qū)地表土壤抗風蝕能力測試研究[D];內(nèi)蒙古農(nóng)業(yè)大學;2006年

5 榮姣鳳;移動式風蝕風洞研制與應(yīng)用[D];中國農(nóng)業(yè)大學;2004年

6 何文清;北方農(nóng)牧交錯帶農(nóng)用地風蝕影響因子與保護性農(nóng)作制研究[D];中國農(nóng)業(yè)大學;2004年

7 臧英;保護性耕作防治土壤風蝕的試驗研究[D];中國農(nóng)業(yè)大學;2003年

8 張金鎖;旋轉(zhuǎn)曲線管道粘性流體流動特性研究[D];浙江大學;2001年

相關(guān)碩士學位論文 前4條

1 劉奇?zhèn)?復雜地形下的風沙流場模擬及輸沙率的計算[D];蘭州大學;2008年

2 王金蓮;布袋式集沙儀結(jié)構(gòu)參數(shù)對集沙效率影響的試驗研究[D];內(nèi)蒙古農(nóng)業(yè)大學;2008年

3 段學友;可移動式風蝕風洞流場空氣動力學特性的測試與評價[D];內(nèi)蒙古農(nóng)業(yè)大學;2005年

4 冬梅;可移動式風蝕風洞集沙儀及排沙器的性能試驗研究[D];內(nèi)蒙古農(nóng)業(yè)大學;2005年

，

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