modelShs_SinglePhase_Overall

Specify Shs | Single Phase | Overall

Extends from PartialSinglePhase (Base model).

Information

Local heat transfer model for fully developed laminar and turbulent flow in circular pipes.

  • The laminar region has been shown to be significantly impacted by the duct shape and wall boundary conditions but not the surface roughness.
  • The turbulent region has been shown to be highly depenedent of surface roughness but not impacted by duct shape or wall boundary conditions.
  • The characteristic dimension is defined as dimension = 4*crossArea/perimeter where "crossArea" is the cross sectional flow area and "perimeter" is the wetted perimeter.

Range of validity:

  • fully developed pipe flow
  • forced convection
  • one phase Newtonian fluid
  • constant wall temperature or constant heat flux in laminar region
  • 0 ≤ Re ≤ 1e6, 0.1 ≤ Pr ≤ 1000, d/L ≤ 1
  • Applies only to circular pipes in the laminar region but can approximate other with the characteristic dimension. Turbulent region is independent of pipe shape.

The correlation takes into account the spatial position along the pipe flow, which changes discontinuously at flow reversal. However, the heat transfer coefficient itself is continuous around zero flow rate, but not its derivative.

References

  1. VDI Heat Atlas 2E, 2010.
  2. Heat Transfer. Nellis and Klein. 2009

Parameters

TypeNameDefaultDescription
Internal Interface
IntegernMT (from PartialMassTransfer)1Number of mass transfer segments
IntegernC (from PartialMassTransfer)1Number of substances
IntegerflagIdeal (from PartialMassTransfer)0Flag for models to handle ideal heat transfer
Advanced
SI.ReynoldsNumberRe_lam (from PartialMassTransfer)2300Laminar transition Reynolds number
SI.ReynoldsNumberRe_turb (from PartialMassTransfer)4000Turbulent transition Reynolds number

Components

TypeNameDefaultDescription
Medium.ThermodynamicState[nMT]states (from PartialMassTransfer)Thermodynamic state of fluid
SI.Temperature[nMT]Ts_wall (from PartialMassTransfer)Wall temperature
SI.Concentration[nMT,nC]Cs_wall (from PartialMassTransfer)Wall concentration
SI.Concentration[nMT,nC]Cs_fluid (from PartialMassTransfer)Fluid concentration
SI.Velocity[nMT]vs (from PartialMassTransfer)Fluid Velocity
SI.Diameter[nMT]dimensions (from PartialMassTransfer)Characteristic dimension (e.g. hydraulic diameter)
SI.Area[nMT]crossAreas (from PartialMassTransfer)Cross sectional flow area
SI.Length[nMT]dlengths (from PartialMassTransfer)Characteristic length of heat transfer segment
SI.Height[nMT]roughnesses (from PartialMassTransfer)Average height of surface asperities
SI.DiffusionCoefficient[nMT,nC]Ds_ab (from PartialMassTransfer)Diffusion coefficient in fluid
SI.MassFlowRate[nMT]m_flows (from PartialMassTransfer)Fluid mass flow rate
SI.ReynoldsNumber[nMT]Res (from PartialMassTransfer)Reynolds number
SI.SchmidtNumber[nMT,nC]Scs (from PartialMassTransfer)Schmidt number
SI.Length[nMT]xs (from PartialMassTransfer)Position of local mass transfer calculation
Units.CoefficientOfMassTransfer[nMT,nC]alphasM (from PartialMassTransfer)Coefficient of mass transfer
Units.SherwoodNumber[nMT,nC]Shs (from PartialMassTransfer)Sherwood number
TRANSFORM.Media.BaseProperties1PhasemediaProps (from PartialSinglePhase)Bulk fluid properties
SI.SchmidtNumber[nMT,nC]Shs_lam{Functions.SinglePhase.InternalFlow.Sh_Laminar_Local_Developed_Circular_SiederTate(Res[i], Scs[i, j], sum(dlengths), dimensions[i]) for i in 1:nMT, j in 1:nC}Laminar Schmidt number
SI.SchmidtNumber[nMT,nC]Shs_turb{Functions.SinglePhase.InternalFlow.Sh_Turbulent_Local_Developed_Circular_DittusBoelter(Res[i], Scs[i, j]) for i in 1:nMT, j in 1:nC}Turbulent Schmidt number
SI.LengthL_chardimensionsCharacteristic dimension for calculation of alphaM