【Daily Question】Fundamentals of Chemical Engineering 581: Viscosity of Fluids (July 3)
Thread Content
This post was last edited by Zaihui Kangqiao on 2017-7-3 at 14:45. The Chemical Engineering Theory section is now launching a \"One Question per Day\" activity to help everyone reinforce their basic knowledge in chemical engineering. Subsequent series such as \"Principles of Chemical Engineering\", \"Mass Transfer and Separation\", \"Thermodynamics in Chemical Engineering\", and \"Chemical Process Engineering\" will also be introduced. We hope for your active support~~~ Replies to the \"One Question per Day\" activity can be viewed directly; the thread will be closed after 1 day! ! To encourage continued participation from everyone this year! Participation earns 3 wealth points, with an additional 4 wealth points for correct answers~~~ Short answer question: The viscosity of a fluid refers to ________________________________________. The viscosity value changes with temperature; for liquids, as the temperature rises, the viscosity________ ； For gases, as the temperature increases, viscosity ________. When fluid is in flow, between adjacent fluid layers, on a unit contact area, the internal friction force decreases or increases when the velocity gradient is 1
The viscosity of a fluid refers to the internal friction force that arises when a fluid is in motion, between adjacent layers of the fluid, per unit area of contact, when the velocity gradient is 1. The viscosity value changes with temperature: it decreases as the temperature of a liquid rises, and it increases as the temperature of a gas rises.
The internal frictional resistance generated by fluid flow； Reduce ； Increase
Fluids that are in different planes but parallel to each other have the same area “A”, are separated by a distance “dx”, and flow in the same direction at different speeds “V1” and “V2”. Newton assumed that the force responsible for this difference in speeds is proportional to the relative velocity or velocity gradient of the fluids; that is: τ=ηdv/dx=ηD (Newton’s formula). Here, η is related to the properties of the material, and it is referred to as “viscosity”. Small Large
The property of internal friction that arises between molecules of a liquid as it flows is known as the viscosity of the liquid, and the magnitude of this viscosity is expressed in terms of viscosity. Decrease. Decrease.
Viscosity is a property of fluids, and different fluids have different viscosity values. The viscosity of the same fluid is significantly dependent on temperature, while it is almost independent of pressure. The viscosity of gases increases as temperature rises, while that of liquids decreases.
The viscosity of a fluid refers to the internal friction force that arises when a fluid is in motion, between adjacent layers of the fluid, per unit area of contact, when the velocity gradient is 1. The viscosity value changes with temperature; for liquids, as the temperature rises, viscosity ____ decreases____ ； For gases, as the temperature increases, viscosity __ increases__.
Viscosity is a property of fluids, and different fluids have different viscosity values. The viscosity of the same fluid is significantly dependent on temperature, while it is almost independent of pressure. The viscosity of gases increases as temperature rises, while that of liquids decreases.
When fluid is in flow, between adjacent fluid layers, on a unit contact area, the internal friction force decreases or increases when the velocity gradient is 1
When fluid is in flow, between adjacent fluid layers, on a unit contact area, the internal friction force decreases or increases when the velocity gradient is 1