The video below shows several different long chained oils, each progressively more viscous. A fluid that is highly viscous has a high resistance (like having more friction) and flows. TURBULENT FLOW When a turbine-type mixer creates turbulence in the lower viscosity ranges (less than 5,000 centipoise), the resulting flow is chaotic. Viscosity is the measure of the resistance of a fluid to flow. Glycerol, CH 2OHCHOHCH 2OH, is viscous partly because of the length of the chain but also because of the extensive possibilities for hydrogen bonding between the molecules. To better understand the ramifications of high-viscosity mixing, let’s first review a much simpler case that of turbulent flow in low-viscosity mixing. Fuel oil, lubricating grease, and other long-chain alkane molecules are quite viscous for this reason. This is because the molecular chains get tangled up in each other like spaghetti-in order for the liquid to flow, the molecules must first unravel. Liquids containing long molecules are invariably very viscous. Pre-heating is of course an option, but the downside is higher energy. Honey, mostly glucose and fructose (see image below) is a good example of a liquid which owes its viscosity to hydrogen bonding. Mineral oils for instance become more viscous, or thicker, at lower temperatures. Liquids whose molecules are polar or can form hydrogen bonds are usually more viscous than similar nonpolar substances. Viscosity is governed by the strength of intermolecular forces and especially by the shapes of the molecules of a liquid. Viscosity is not a dimensional measurement, so calling highly viscous oil thick and less viscous oil thin is misleading. Sometimes, viscosity is erroneously referred to as thickness (or weight). Those like ether or gasoline which flow very readily have low viscosities. Generally speaking, viscosity is a fluid’s resistance to flow (shear stress) at a given temperature. Liquids which flow very slowly, like glycerin or honey, have high viscosities. However, the high internal friction of the oil may offer greater resistance to the movement of the lubricating parts. 17 of the randomized hips were classified as drop- outs peroperatively (Table 1). The study was approved by the Ethics Committee and the Medical Product Agency. The resistance to such flow is called the viscosity. Fol- low-up examinations were performed after 3-6, 12, 24, and 60 months. In order for the flat viscosity oil to be widely used in the world, it is necessary to establish new engine oil specification.\)īecause its molecules can slide around each other, a liquid has the ability to flow. As a result, CO 2 reduction can be achieved not only for new vehicles but also for vehicles in operation in the market that can contribute greatly to the carbon neutrality. The flat viscosity 0W-16 will improve the fuel economy of in-use vehicles calibrated with conventional 0W-16 oils in the market significantly.
This technology is applicable for vehicles calibrated with either 0W-16 or 0W-8 without negative impact on fuel economy performance. It proved the possibility to achieve fuel economy equal to or better than 0W-8 while maintaining 0W-16 equivalent high temperature viscosity. The flat viscosity oil can be achieved by using a low-evaporative, low-viscosity base oil and an ultra-high viscosity index Viscosity Modifier.
In order to achieve both of these characteristics, an oil whose viscosity has smaller temperature dependency (flat viscosity oil) is required. On the other hand, the viscosity must be kept above a certain level to ensure the performance of hydraulic devices in the high oil temperature range. Therefore, the reduction of viscous resistance in the mid-to-low temperature range below 80☌ is expected to contribute more to fuel economy. Since HEV requires less work from the engine, the engine oil temperature is lower than that of conventional engine vehicles. For such vehicles, low-viscosity engine oil will be one of the most important means to contribute to further reduction of CO 2 emissions. Although interest in BEV is currently growing, vehicles equipped with internal combustion engines (ICE) including HEV and PHEV will continue to be used in areas where conversion to BEV is not easy due to lack of sufficient infrastructures. In recent years, the realization of carbon neutrality has become an activity to be tackled worldwide, and automobile manufacturers are promoting electrification of power train by HEV, PHEV, BEV and FCEV.
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