![]() So, we highly recommend giving our Combo package a try to enhance your knowledge on the subject. Mathematically, surface tension can be expressed as follows: TF/L. Watching the videos will help you grasp the topic better and make learning more enjoyable. Surface tension is defined as, The ratio of the surface force F to the length L along which the force acts. ![]() This package covers all the important details and presents them in an easy-to-understand format. ![]() It’s a great way to dive deeper into the subject through video explanations. If you want to learn more about this topic, we suggest checking out our Combo package with the given link . We want a higher viscosity index in lube oils because a good quality lube oil should not change its viscosity w.r.t change in temperature and a lower viscosity index in fuel oils because we want the viscosity to change w.r.t change with temperature. Lower viscosity index: more viscosity is affected with a change in temperature Higher viscosity index: less viscosity is affected with a change in temperature. Viscosity and density are two different terms where viscosity is the thickness of fluid and density refers to the space between its particles. Therefore, water has a viscosity of 0.0091 poise. In CGS unit, the value of viscosity is 8.90 × 10- 3 dyn·s/cm2 or 0.890 cP. It is the change in viscosity relative to temperature change. In the SI unit, the value of viscosity is 8.90 × 10 - 4 Pa·s. It can be measured by a device called a viscometer.ĭiagrams: Capillary type viscometer Falling ball-type viscometer Rotary type viscometer What is the Viscosity index? So viscosity is important in looking at how much is the clearance, if clearance is less, then we need less viscous lube oil otherwise it will not enter the between two surface clearances. We need to lubricate it so that it does not create friction and get wear and tear. When we have two metals, one is stationary and the other is moving up and down, the clearance between both metals is very less. This unit can be combined with time (sec) to define dynamic viscosity. So when fuel is heated, its viscosity reduces and proper injection takes place. The Pascal unit (Pa) is used to describe pressure or stress force per area. It is very thick at 30° C so for burning it, we heat it to 130° C so that it can have a viscosity of 13 cst, the fuel we get on the ship has actual viscosity of 380 cst which is very thick at 50☌. The quality of fuel on the ship is third-grade quality. The coefficient of viscosity of a liquid is defined as the viscous force acting tangentially per unit area of a liquid layer having a unit velocity gradient in. Viscosity ∝ 1/Temp (for liquid) Why is viscosity important onboard a ship? Example: honey when in very cold temp like 15° C is very thick and will not flow easily, raise it to 45° C then the flow will increase and at 80° C it will flow like water. Increasing the temperature of a substance decreases its viscosity which increases flow. All heavy oils and lube oils used on the ship are denoted by viscosity in cst at 50 ☌ Viscosity and its relation with temperature:
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |