UC知道这道流体力学题的正确答案是多少
来源：百度知道 编辑：UC知道 时间：2024/05/10 19:00:57
A 12-kg cube slides down an inclided plane making an angle of 30°with the horizontal. A fluid film 0.1mm thick separates solid and surface. The fluid viscosity is 0.04 newton-seconds per square meter. Assuming the velocity distribution in the film is linear, find the terminal velocity of the block. The area of the cube in contact with the film is 0.25 square meters.
A 12-kg cube slides down an inclined plane making an angle of 30°with the horizontal. A fluid film 0.1mm thick separates solid and surface. The fluid viscosity is 0.04N.s/m2. Assuming the velocity distribution in the film is linear, find the terminal velocity of the block. The area of the cube in contact with the film is 0.25 m2.
哪位能告诉我这道题的正确答案 先谢谢了！
A 12-kg cube slides down an inclined plane making an angle of 30°with the horizontal. A fluid film 0.1mm thick separates solid and surface. The fluid viscosity is 0.04N.s/m2. Assuming the velocity distribution in the film is linear, find the terminal velocity of the block. The area of the cube in contact with the film is 0.25 m2.
哪位能告诉我这道题的正确答案 先谢谢了！
粘性力成为立方体下滑的阻力，重力沿倾斜平板的分量是动力。最终速度就是力平衡时的速度。
粘性应力τ=μ*V/d,其中μ为液体的动力粘性，V为立方体的最终速度，d为薄膜厚度。
那么阻力f=τ*S,其中S为立方体和薄膜的接触面积。
动力为mg*sin30°=m*g/2
平衡：m*g/2=μ*V/d*S
代入数字： 12*9.8/2=0.04*V/0.1e-3*0.25
可以得到最终速度 V=0.588 m/s