Both the types of COF can be expressed by the same … The coefficient of friction is a ratio used to quantify the friction force between two objects in relation to the normal force that is keeping them together. A coefficient of friction is a value that shows the relationship between two objects and the normal reaction between the objects that are involved. As water passes through a hose, friction between the water and the inside surface of the hose causes turbulence, which slows the water. It is a value that is sometimes used in physics to find an object's normal force or frictional force when other methods are unavailable.. The results in a PSI drop (pressure … Friction coefficient table for various material pairs in atmosphere and vacuum (see the definition of friction coefficient) is shown below.The data was collected from various sources [1,2,3]. For example, static friction can prevent an object from sliding down a sloped surface. The friction in liquids is different from friction between solids as , between solids, friction can be big when they aren't sliding and drops some when they start to slide. Friction coefficient dependences on the initial Hertzian stress of the diamond film with and without water lubrication are shown in Fig.6.Without water lubrication, the relationship between the friction coefficient of diamond film can be expressed as single curves, so-called “master curves”, independent of the opposing tip radius. The Friction coefficient is a constant for a pair of surfaces (made of same or different materials) in contact which decides the amount of frictional force generated at the common layer when one surface moves or tends to move with respect to the other surface. Friction Loss Explained. The friction factor or Moody chart is the plot of the relative roughness (e/D) of a pipe against the Reynold's number. Friction loss occurs when water passes through a hose. The coefficient of static friction, typically denoted as μ s, is usually higher than the coefficient of kinetic friction. The coefficient of friction is shown by =.In that equation, is the frictional force, is the coefficient … In this equation, h L represents friction head loss (meters of H2O), L represents length of pipe (meters), d represents internal pipe diameter (meters), Q represents flow rate through the pipe (cubic meters per second), and C represents the Hazen-Williams coefficient, which will vary according to how smooth the internal … RE: Friction coefficient for steel on steel with a water film between chicopee (Mechanical) 5 Sep 04 23:54 since I dont believe that a water film can be maintained before movement assume the static coeffecient of friction to be around .15 to get things moving. The coefficient of friction is an important consideration during material selection and surface requirement determination. In a liquid, the faster something moves through the … Image Source: Wiki. during motion I'll guess that value will drop at least 50% K = loss coefficients for minor losses V = fluid velocity, m/s (ft/sec) g = gravitational acceleration, 9.81 m/sec 2 (32.2 ft/sec 2) The friction factor, f, is a function of the relative roughness of the piping material and the Reynolds number, R e. Where: R e = Reynolds number D i = inside pipe diameter, m (ft) Static friction is friction between two or more solid objects that are not moving relative to each other. Friction Loss of Water in Pipe Fittings in Terms of Equivalent Length - Feet of Straight Pipe; Nominal pipe size Actual inside diameter inches d Friction factor f Gate valve-full open 90° elbow Long radius 90° or 45° sth elbow Sth tee-thru flow Sth tee-branch flow Close return bend Swing check valve-full open Angle valve-full … Fig.1: Showing the Concept of Coefficient of Friction . Static and Kinetic coefficient of friction . The blue lines plot the friction factor for flow in the wholly turbulent region of the chart, while the straight black line plots the friction factor for flow in the wholly laminar region of the chart. Friction coefficient table of solid lubricants, metals, plastics and anti-friction materials. The static and kinetic friction coefficient values reference table shown in this article will be helpful for finding the COF values of commonly used materials. Hose length, diameter, and GPM (volume) all affect friction loss.