割前脱联合收获机吸运风机降耗

为了降低气吸式4ZTL-1800割前摘脱稻（麦）联合收获机吸运风机的能耗，利用拉格朗日法的离散相模型对风机内杂余物料的运动进行了数值计算，得到了颖壳、短茎秆在风机内的运动规律，物料在风机内叶轮的带动下沿轴向和径向进行运动且速度逐渐增加，当运动到蜗壳时，运动方向发生改变且速度降低，且绝大部分杂余物料沿风机出口的上壁排出。气流携带物料及物料的逆流运动消耗一部分风机的能量。且噪声是能耗的一部分，结合数值计算结果进行试验研究，在风机出口布置吸声材料，使风机的噪声降低。该研究为降低风机的能耗提供参考依据。

Decreasing power consume of fan in combine harvester threshing prior to cutting with air suction

In order to decrease power consume of fan in 4ZTL-1800 combine harvester threshing prior to cutting with air suction, traces of chaffies and short straws moving in the fan were tracked by discrete phase model of Lagrange in numerical simulation. Their moving laws were as follows. Chaffies and straws moved under force of rotor rotating in the fan, and so which axial and radial speeds increased gradually. When they moved to the volute, their speeds were decreased and their moving directions were changed. Most of chaffies and straws exhausted along the upper wall of fan. Part of fan power was consumed by airflow taking chaffies and short straws and their eddy moving. Because noise was part of power consume, according to the results of numerical simulation, the test was done about the effect of muffle fixed at exit of the fan on fan noise and fan noise was decreased. The results are beneficial to decrease power consume of fan.