Species Table  Transport Properties
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Viscosity
This field is optional and only visible for liquid or gas species.
The unit for Viscosity is Ns/m²
User can use a number formats for entering viscosity data into the SysCAD database:
 Constant  User can enter a constant value
 Equations for Liquid in various forms, see Liquid Viscosity.
 Equation for gases.
NOTE:
 Some of the equations require data to be entered in specific units. This is generally to match the most commonly available published information. The user may need to convert their data to match the required units of measure.
Viewing Results in SysCAD
If viscosity data is added, the individual Species Viscosity data (liquid and gas) can be viewed in SysCAD from the $SDB window (Species  View Properties).
The stream Viscosity data can be viewed in SysCAD by enabling the Transport Properties group, either by
 from "Plant Model  Views tab page", select the "Transport" tickbox or
 by pressing the "Include Properties" button on the pipe Qo tab and select "Transport"
Liquid Viscosity
Liquid Mixture Viscosity
The liquid viscosity ([math]\displaystyle{ \mu_m }[/math]) is calculated using mass weighted logarithmic mixing:
 [math]\displaystyle{ \mathbf{\mathit{\ln{\mu_m} = \sum{m_i * \ln{\mu_i}}}} }[/math]
 Where
[math]\displaystyle{ \mu_m }[/math] = Solution Viscosity [math]\displaystyle{ \mu_i }[/math] = Viscosity of component i m_{i} = mass fraction of component i
We can separate water and solutes and describe the liquid viscosity ([math]\displaystyle{ \mu_m }[/math]) calculation using the water viscosity ([math]\displaystyle{ \mu_w }[/math]) and the solutes viscosity ([math]\displaystyle{ \mu_i }[/math]) using following equation:
 [math]\displaystyle{ \mathbf{\mathit{\ln{\mu_m} = m_w * \ln{\mu_w} + \sum{m_i * \ln{\mu_i}}}} }[/math]
 Where
[math]\displaystyle{ \mu_m }[/math] = Solution Viscosity [math]\displaystyle{ \mu_w }[/math] = Viscosity of water [math]\displaystyle{ \mu_i }[/math] = Viscosity of solute i m_{w} = mass fraction of water m_{i} = mass fraction of solute i
The viscosity for each solute ([math]\displaystyle{ \mu_i }[/math]) can be defined in a number of formats, these are described in the following sections:
 Laliberte´ Viscosity Function format
 Andrade equations format
 Vogel equation format
 Prausnitz equation format
 Prausnitz  Vogel equation format
Laliberte´ Viscosity Function
SysCAD Format  General Equation  Description  

Laliberte_Visc(v1, v2, v3, v4, v5, v6) 
The viscosity for each solute ([math]\displaystyle{ \mu_i }[/math]) is defined by: [math]\displaystyle{ \mu_i = \cfrac {e^{\left [ \cfrac{v_1(1m_w)^{v_2}+v_3}{(v_4*T+1)} \right ]}} {(v_5(1m_w)^{v_6}+1)} }[/math] 
Where
If the user has appropriate constants for the Laliberte´ equation for aqueous species, then they can select this equation to calculate viscosity as a function of MF & T. Example NaCl(aq): Laliberte_Visc(16.22178863, 1.322930868, 1.48485985, 0.007469126, 30.78020075, 2.058268523):Range(C, 5.0, 154.0) 
Laliberte´ Viscosity Reference and Notes
REFERENCE:
 Laliberte´ M. Model for Calculating the Viscosity of Aqueous Solutions J. Chem. Eng. Data 2007, 52.
NOTES:
 The constants for most aqueous species are valid for temperatures between approximately 5 and 120°C.
 If the unit temperature is outside of the species temperature range, then SysCAD will use the values at the temperature limit.
 The user MUST define all 6 constants and also the valid range for the function.
 This method calculates the viscosity of a solution based on ALL of the aqueous species dissolved in the solution. Therefore, if the user wishes to use this method, then it is recommended that all aqueous species in a project use the Laliberte´ method for the results to be consistent.
 At present, the SysCAD Species database entry does not support the Laliberte Format, user needs to manually specify the equation directly into the data field, thus, do not use the Edit User Data Dialog box via the button.
 Calculations using the viscosity correlation should be treated as indicative only and use of the numbers in detailed design should be discouraged. Laboratory testing of liquors should be undertaken to provide accurate viscosity measurements for design of equipment.
Other forms of Liquid Viscosity Equation
Equation Type  SysCAD Format  General Equation  Notes 

Andrade Equation Format 
Andrade(a,b) 
The most commonly used Liquid Viscosity function is the Andrade equation: [math]\displaystyle{ \mu_i = a * e^{b/T} }[/math] 
Where:
Please see Reference literature for values of a, b, c and d. 
Andrade(a,b,c,d) 
Andrade equation with 4 term exponential [math]\displaystyle{ \mu_i = a * \exp{\left( \frac{b}{T} + c T + d T^2 \right)} }[/math]  
Vogel Equation Format 
Vogel(a,b,c) 
Vogel equation with 3 term exponential [math]\displaystyle{ \mu_i = a * \exp{\left( \frac{b}{Tc} \right)} }[/math]  
Prausnitz Equation Format  The following Prausnitz equation formats are used for entering viscosity data into the SysCAD database:  
PrausnitzPow(a,b) 
Power equation [math]\displaystyle{ \mu_i = a * T^b }[/math]  
Prausnitz(a,b) 
Modified Andrade equation with 2 term exponential [math]\displaystyle{ \ln{\mu_i} = a + \frac{b}{T} }[/math] [math]\displaystyle{ \mu_i = \exp \left ( a + \frac{b}{T} \right ) }[/math]  
Prausnitz(a,b,c,d) 
Modified Andrade equation with 4 term exponential [math]\displaystyle{ \ln{\mu_i} = a + \frac{b}{T} + cT + dT^2 }[/math] [math]\displaystyle{ \mu_i = \exp \left ( a + \frac{b}{T} + cT + dT^2 \right ) }[/math]  
PrausnitzVogel Equation Format 
PrausnitzVogel(a,b,c) 
PrausnitzVogel equation with 3 term exponential [math]\displaystyle{ \ln{\mu_i} = a + \frac{b}{T+c} }[/math] [math]\displaystyle{ \mu_i = \exp{\left(a + \frac{b}{T+c} \right)} }[/math] 
REFERENCE:
 The Properties of Gases and Liquids. Reid & Prausnitz. 4th Edition
NOTES:
 These equations are generally for “pure liquids” and Temperature range are normally between freezing point to boiling point of the compound.
 At present, these equations have not be implemented with temperature ranging, user needs to check manually if the stream temperature is within reasonable temperature range.
 These simple equations are all empirical, they are not reliable and use of the numbers in detailed design should be discouraged. Laboratory testing of liquors should be undertaken to provide accurate viscosity measurements for design of equipment.
Liquid Viscosity Equation for Alumina Species Model
For users using the Alumina species model, the liquor and slurry viscosity is estimated using inbuilt equations, see Viscosity.
The calculated viscosity can be viewed in SysCAD by enabling the Transport Properties group, either by
 selecting the "Transport" tickbox from "Plant Model  Views tab page" or
 by pressing the "Include Properties" button on the pipe Qo tab and select "Transport"
Gas Viscosity
Equation Type  SysCAD Format 

Constant  Simply enter a constant into the field. 
Thodos Equation 

Thermal Conductivity
This field is optional and only visible for liquid or gas species.
The unit for Thermal Conductivity is W/m.K.
User can use a number formats for entering thermal conductivity data into the SysCAD database:
 Constant  User can enter a constant value
 Polynomial equation based on temperature
 Equations for gases based on paper by Misic and Thodos.
 The Misic and Thodos Equation is a function of Cp and T. Other species properties such as molecular weight and critical properties (Tc and Pc) are also used to calculate the thermal conductivity, k, so if Tc or Pc is missing, then species database errors will be given on project load.
 Two equation formats have been implemented in Build138.25032 based on the paper from Misic and Thodos (note unit conversions from original paper);
Polynomial Format
SysCAD Format  General Equation  Description / Notes 

Poly_TC(C0,C1,C2,C3) 
[math]\displaystyle{ k = C_0 + C_1 T + C_2 T^2 + C_3 T^3 \, }[/math] 
where T  Temperature in K NOTE: The Poly_TC will support up to 4 terms, user can ignore the later constants if the polynomial has less terms. 
Misic and Thodos Equation Formats
SysCAD Format  General Equation  Description  Notes  

MisicThodos1() 
[math]\displaystyle{ \left ( \frac {k \lambda} { Cp } \right ) * 10^{4} = \left ( 14.52*T_R  5.14 \right )^{2/3} }[/math]

Where:

This equation is suitable for all types of hydrocarbon gases (aliphatic compounds), where the reduced temperature, T_{R}, is between 0.5 and 3.  
MisicThodos2() 
[math]\displaystyle{ \left ( \frac {k \lambda} { Cp } \right ) = 0.445 * 10^{3} * T_R }[/math]

This equation is suitable for methane, naphthene and aromatics gases, where the reduced temperature, T_{R}, is below 1. 
Reference:
 "The Thermal Conductivity of Hydrocarbon Gases at Normal Pressure"  Dragoslav Misic and George Thodos. A.I.Ch.E Journal, pp264, June 1961