The EN 14214 is more rigorous for this parameter, and some microalgae-based biodiesels do not meet this specification as seen in Table 10.4 because most microalgae species show a high degree of unsaturation and long-chain fatty acid contents. Factors such as growing conditions and lipid extraction may affect the fatty acid profile and consequently the biodiesel properties ( Soares et al., 2014). Kinematic Viscosity is the ratio of absolute or dynamic viscosity to density - a quantity in which the force is external and independent of the mass of the. However, in another study ( Song et al., 2013), this microalgae-based biodiesel was according to the specification (4.5 mm 2 s − 1). For the Brazilian standard, only Phaeodactylum tricornutum presents biodiesel with KV (2.9 mm 2 s − 1) slightly lower than the minimum established ( Gangadhar et al., 2015). The biodiesel viscosity from oilseeds, animal fat, and microalgae are in accordance with the ASTM standard. As shown in Table 10.4, biodiesel presents greater viscosity than diesel due to a higher degree of unsaturation and by oxidation reactions that can modify the fatty acid composition during storage, transportation, and temperature change ( Knothe and Steidley, 2007). Kinematic viscosity (KV) is a physical property related to the chain length and degree of saturation thus, this criterion is associated with oxidation stability and IV. Use this simple science kinematic viscosity calculator to calculate density. Tzovenis, in Microalgae-Based Biofuels and Bioproducts, 2017 10.4.3 Kinematic viscosity It appears Stokes and Poise got the same answer just in two different ways.L. If you divide kinematic viscosity by the fluid density, you get absolute viscosity. Thus, dynamic viscosity is a measure of force, while kinematic viscosity is a measure of velocity. Kinematic viscosity incorporates fluid density as part of its measurement.
This means the fluid’s weight or density helps it to flow. There is no external force pushing the fluid. It is the time it takes to have a known amount of fluid flow a given distance. The formula for kinematic viscosity is 1 centistoke (cSt) equals 1 millimeter squared per second (mm 2/s). This viscosity measurement was given the term kinematic. Again, centistokes (cSt) is used for easier readings. These tests led to Stokes’ law and a different form of viscosity measurement. He tested this theory by putting fluid in a glass tube and measuring how long it took for the fluid to flow a certain distance. Stokes surmised there was some type of internal friction in the fluid causing the different rates of falling. He discovered that the same particle sank at different rates in different fluids. Therefore, this type of viscosity measurement requires an external force in order to be measured.Ībout the same time Poise was performing his tests, an Irishman named Sir George Stokes was dropping particles into fluids and measuring how fast they fell to the bottom. Related Articles: Five Sense Organs For Kids Of Class 1 And 2 Glycolysis: Pathway. Kinematic viscosity is more beneficial than absolute or dynamic viscosity in a few instances. In actuality, they are rather different from one another. Pascal is a unit of force just like horsepower. F force: Mue viscosity of the fluid: A area of each plate.
The formula for dynamic or absolute viscosity is 1 centipoise (cP) equals 1 millipascal-second (mPa-s). It is directly proportional to the absolute viscosity but inversely proportional. Its unit of measurement is newton seconds per meter square (Ns/m 2 ), and the dimensional formula is given by M 1 L -1 T -1. The term dynamic or absolute is used for this viscosity measurement. The formula for kinematic viscosity is given by the ratio of absolute viscosity to the density of the fluid. To make readings easier, centipoise (cP) is preferred for lubricant viscosities. This internal friction is measured by the force needed to make it flow and was given the measurement name of poise. Dynamic viscosity: Kinematic viscosity: Formula: values: Density: Example 1: 5: 2: Dynamic viscosity / Kinematic viscosity: 7/2: 3.5: Example 2: 13: 3: Dynamic viscosity / Kinematic viscosity: 13/3: 4. This led him to conclude that different fluids have an internal friction which must be overcome by an external force in order to flow. Poiseuille found that different blood flowed at different speeds through the glass tubes with the same amount of force. This article explains the differences.Īround 1840, a French mathematician named Jean Leonard Marie Poiseuille conducted tests involving the flow of blood through small glass tubes. This resistance is measured by two different methods. The definition of lubricant viscosity is the fluid’s resistance to flow and shear. Viscosity is the utmost characteristic of a lubricant.