Material Category (Material)

These are properties related to the material from which the device is made/coated and vary according to the type of device:

• Manning coefficient (ACMan, Double) - roughness, used in the Manning formula
  For the flow of a fluid to occur, it must be subject to a accelerating force. Once this force is applied, in the region of contact between the fluid and the wetted perimeter of a certain channel, a resistance force appears that opposes the movement and is mainly responsible for head loss in uniform flows and gradually varied. This last force is a function of fluid viscosity and roughness. of the channel (PORTO, 2006).
  The factor associated with roughness most used in practical problems involving free conduit flow is the Manning coefficient
  Typical Manning Coefficient values:

  Closed Conduits
  Conduit Material	Manning coefficient
  Asbestos-cement pipe	0.011 - 0.015
  Brick	0.013 - 0.017
  Cast iron pipe
  - Coated with cement and coated with seal	0.011 - 0.015
  Concrete (monolithic)
  - Smooth shapes	0.012 - 0.014
  - Coarse Forms	0.015 - 0.017
  Concrete pipe	0.011 - 0.015
  Corrugated Metal Tube (1/2"X 2-2/3" dimples)
  - Simple	0.022 - 0.026
  - Inverted paving	0.018 - 0.022
  - Lined spun asphalt	0.011 - 0.015
  Plastic pipe (smooth)	0.011 - 0.015
  Glazed clay
  - Pipes	0.011 - 0.015
  - Coating boards	0.013 - 0.017
  Open Channels
  Aligned channels
  - Asphalt	0.013 - 0.017
  - Brick	0.012 - 0.018
  - Concrete	0.011 - 0.020
  - Debris or riprap	0.020 - 0.035
  - Vegetable	0.030 - 0.040
  Excavated or Dredged
  - Earth, straight and even	0.020 - 0.030
  - Earth, winding, fairly even	0.025 - 0.040
  - Rock	0.030 - 0.045
  - No maintenance	0.050 - 0.140
  Natural channels (smaller creeks, upper width at flood stage < 100 feet)
  - Quite regular section	0.030 - 0.070
  - Transect with pools	0.040 - 0.100

  
  Source: ASCE (1982). Gravity Sanitary Sewer Design and Construction, ASCE Manual of Practice No. 60, New York, NY.
  
  Chezy-Manning formula for head loss:
  HL = 4.66 * n ^ 2 * L * Q ^ 2 / ( d ^ 5.33 )
  Where:
  HL = head to toe loss
  Q = flow in cfs
  L = pipe length in feet
  d = pipe diameter in feet
  n = Manning roughness coefficient
• Hazen-Williams Coefficient (ACHW, Double) - Over the years, networks and water mains have decreased their flow condition due to incrustations, mainly cast iron, asbestos or steel lines . The degree of resistance to flow is determined by the “C” coefficient of Hazen - Williams. The smaller this coefficient, the greater the head loss imposed on the flow and, consequently, the more energy is required to overcome this resistance. This is reflected in lower-than-expected outflows, reduced pressures at the most distant points and high pressures at the closest points, high energy consumption in the discharges and very large variations in pressure throughout the day. Hazen-Williams formula:
  HL = 4,727 * L * Q ^1,852 / ( C ^ 1,852 ) * d ^ 4,871
  Where:
  HL = head to toe loss
  Q = flow in cfs
  L = pipe length in feet
  d = pipe diameter in feet
  C = roughness coefficient (Hazen-Williams C Factor)
• Darcy-Weisbach coefficient (ACDW, Double) - The friction factor or Darcy-Weisbach coefficient of resistance, sometimes referred to as the friction factor (f) is a dimensionless parameter that is used to calculate the Head Loss in a pipe due to friction.
  The calculation of the friction factor and the influence of two parameters (Reynolds number Re and relative roughness er) depends on the flow regime.
  Darcy-Weisbach formula for head loss:
  HL = f * L * v ^ 2 / (d * 2* g)
  Where:
  HL = Head Loss (length)
  g = Gravity Acceleration (Length / Time / Time)
  L = pipe length (length)
  d = pipe diameter (length)
  v = flow velocity (length / time)
  f = friction factor (unitless)

Typical roughness coefficients: