ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

Aiming at the problems of high resistance, high energy consumption of traction in subsoiling, low operation efficiency, cultivated layer restoration and soil remediation, an active lubricating drag reduction scheme for curved subsoiler for low water content and high compactness farming soil was proposed. Firstly, on the basis of the three-dimensional model of the curved subsoiler obtained by three-dimensional scanning, the interaction between the subsoiler and the soil particles during the operation of the curved subsoiler was analyzed by the discrete element method, and the maximum friction contact surface of the subsoiler body was determined as the active lubrication drag reducing surface. Secondly, the idea of active lubricating drag reduction was proposed, and the body fluid distribution and body surface texture of earthworm were used for reference. To form the active lubrication and drag reducing curved subsoiler, the surface configuration in the form of groove, the structure of the lubricating surface such as throttle hole and the pumping system of the lubricating medium were designed on the maximum friction contact surface of the subsoiler surface and the subsoiler tip, respectively. Finally, the operation speed and lubricating fluid flow rate were used as the test factors, and the horizontal operation resistance was the main indicator. Field tests were carried out under two soil conditions. The test results showed that in the brown soil environment, when the operating speed was 3km/h and the lubricating fluid flow rate was 12L/min, the drag reduction rate could reach 13.48%. In the saline-alkali environment, when the operating speed was 1.87km/h and the lubricating fluid flow rate was 12L/min, the drag reduction rate could reach 19.87%. It was preliminarily proved that the active lubricating drag reduction operation mode had a good drag reduction effect in the soil with low moisture content and high compactness.