Thus the difficulties of discontinuous velocitygradient and the stress singularity at the exit point are avoided, and the expense of computation is reduced.
这样回避了速度梯度间断的困难，缓和了出口处应力奇性引起的矛盾，同时又减少了计算量。
2
But for the continuous jet which velocitygradient is not linear, it has not only one virtual origin.
但对于非线性速度分布的连续射流，存在的虚拟原点不是唯一的。
3
An instrument for measuring the viscosity of a fluid by passing the fluid at a known pressure gradient or velocity through a length of tubing of known diameter.