Roughness

Real type for roughness of a pipe

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

This Real type defines the absolute roughness of the inner surface of a pipe or fitting, i.e., the absolute average height of surface asperities. It has usually to be estimated. In [Idelchik 1994, pp. 105-109, Table 2-5; Miller 1990, p. 190, Table 8-1] many examples are given. As a short summary:

Type of pipe Roughness
Smooth pipes Drawn brass, copper, aluminium, glass, etc. 0.0025 mm
Steel pipes New smooth pipes 0.025 mm
Mortar lined, average finish 0.1 mm
Heavy rust 1 mm
Concrete pipes Steel forms, first class workmanship 0.025 mm
Steel forms, average workmanship 0.1 mm
Block linings 1 mm

References

Idelchik I.E. (1994):
Handbook of Hydraulic Resistance. 3rd edition, Begell House, ISBN 0-8493-9908-4
Miller D. S. (1990):
Internal flow systems. 2nd edition. Cranfield:BHRA(Information Services).

Type Information

Real

Quantity: Length

Unit: m

Display Unit: mm

Restricted Range: 0 to +Inf

Used in Components (9)

BasicHX

Modelica.Fluid.Examples.HeatExchanger.BaseClasses

Simple heat exchanger model

PartialStraightPipe

Modelica.Fluid.Pipes.BaseClasses

Base class for straight pipe models

PartialTwoPortFlow

Modelica.Fluid.Pipes.BaseClasses

Base class for distributed flow models

PartialStaggeredFlowModel

Modelica.Fluid.Pipes.BaseClasses.FlowModels

Base class for momentum balances in flow models

PartialFlowHeatTransfer

Modelica.Fluid.Pipes.BaseClasses.HeatTransfer

base class for any pipe heat transfer correlation

TestWallFrictionAndGravity

Modelica.Fluid.Pipes.BaseClasses.WallFriction

Pressure loss in pipe due to wall friction and gravity (only for test purposes; if needed use Pipes.StaticPipe instead)

TestWallFriction

Modelica.Fluid.Fittings.BaseClasses.QuadraticTurbulent

Pressure drop in pipe due to wall friction (only for test purposes; if needed use Pipes.StaticPipe instead)

Geometry

Modelica.Fluid.Fittings.BaseClasses.Bends.CurvedBend

Geometric data for a curved bend

Geometry

Modelica.Fluid.Fittings.BaseClasses.Bends.EdgedBend

Geometric data for a curved bend