Normally, an increase in pressure causes a fluid’s viscosity to increase, too. Three factors determine a substance’s flow behavior. Still, shear rate is not the only influencer. To learn more consult “ The Rheology Handbook”. The flow behavior of non-Newtonian liquids can be far more complex than these basic examples. yogurt), while for others the viscosity increases with increasing shear rate (curve 3 | e.g.

If its viscosity changes with the shear rate, a liquid is non-Newtonian and – for exact definition – one has to specify the apparent viscosity.ĭifferent shear-dependent fluids behave differently: For some, their viscosity decreases when the shear rate increases (curve 2 | e.g. Typical Newtonian liquids are water or salad oil. For a Newtonian liquid, this function is a straight line (curve 1) see figure 6. Such fluids are named ‘Newtonian liquids’ after Sir Isaac Newton.Ī viscosity function shows the viscosity over the shear rate. the shear rate – acting upon the fluid, it is ideally viscous. If a fluid’s internal flow resistance is independent of the external force – i.e. High-viscosity fluids resist deformation. Fluids which flow easily show a low resistance to deformation. viscous fluids that contain an elastic portion. The specific field of viscometry covers ideally viscous fluids, and – considering certain restrictions – also viscoelastic liquids, i.e. sweet jelly) or as a viscoelastic liquid (like e.g. According to a material’s properties, we either classify it as a viscoelastic solid (like e.g. That is, substances which are neither completely elastic, nor entirely viscous. In everyday life, we mostly come across viscoelastic materials. Scientists specify solid materials as being elastic and liquids as being viscous. Imagine all materials as classified on a virtual scale from solid to liquid. Rheology deals with the flow behavior and deformation of materials. ĭensity of crude oil, Density of fuel oils, Density of lubricating oil and Density of jet fuel as function of temperature.Īs shown in the figures, the change in density is not linear with temperature - this means that the volumetric expansion coefficient for water is not constant over the temperature range.In order to determine a fluid’s viscosity, you have to enter the field of viscometry, a subject area of a wider science called rheology. See also other properties of Water at varying temperature and pressure: Boiling points at high pressure, Boiling points at vacuum pressure, Dynamic and kinematic viscosity, Enthalpy and entropy, Heat of vaporization, Ionization Constant, pK w, of normal and heavy water, Melting points at high pressure, Prandtl number, Properties at Gas-Liquid Equilibrium Conditions, Saturation pressure, Specific gravity, Specific heat (heat capacity), Specific volume, Thermal conductivity, Thermal diffusivity and Vapour pressure at gas-liquid equilibrium.įor other substances, see density and specific weight o f acetone, air, ammonia, argon, benzene, butane, carbon dioxide, carbon monoxide, ethane, ethanol, ethylene, helium, hydrogen, methane, methanol, nitrogen, oxygen, pentane, propane and toluene. See Water and Heavy Water for thermodynamic properties at standard condtions. The density of water depends on temperature and pressure as shown below: Temperature Choose the actual unit of temperature: Note! Temperature must be within the ranges 0-370 ☌, 32-700 ☏, 273-645 K and 492-1160 °R to get valid values. The output density is given as g/cm 3, kg/m 3, lb/ft 3, lb/gal(US liq) and sl/ft 3. The calculator below can be used to calculate the liquid water density at given temperatures. See more about the difference between mass and weight Online Water density Calculator The density of water is 1.940 sl/ft 3 at 39 ☏ (4 ☌), and the specific weight in Imperial units is In the Imperial system the mass unit is the slug, and is derived from the pound-force by defining it as the mass that will accelerate at 1 foot per square second when a 1 pound-force acts upon it:ġ = 1 * 1 and 1 = 1 /1 In the SI system, specific weight of water at 4☌ will be: G = acceleration due to gravity, units typically and value on Earth usually given as 9.80665 m/s 2 or 32.17405 ft/s 2 Specific weight is the ratio of the weight to the volume of a substance: Pure water has its highest density 1000 kg/m 3 or 1.940 slug/ft 3 at temperature 4☌ (=39.2☏). Density is the ratio of the mass to the volume of a substance:

Specific viscosity units