# Functions to calculate water properties: density, specific weight, dynamic and kinematic viscosity, saturation vapor pressure, surface tension, and bulk modulus.

Source:`R/water_properties.R`

`waterprops.Rd`

This function calculates water properties that are used in other functions.

## Usage

```
dvisc(T = NULL, units = NULL, ret_units = FALSE)
dens(T = NULL, units = NULL, ret_units = FALSE)
specwt(T = NULL, units = NULL, ret_units = FALSE)
kvisc(T = NULL, units = NULL, ret_units = FALSE)
svp(T = NULL, units = NULL, ret_units = FALSE)
surf_tension(T = NULL, units = NULL, ret_units = FALSE)
Ev(T = NULL, units = NULL, ret_units = FALSE)
```

## Arguments

- T
the water temperature [\(^{\circ}C\) or \(^{\circ}F\)]

- units
character vector that contains the system of units [options are

`SI`

for International System of Units and`Eng`

for English (US customary) units. This is used for compatibility with iemisc package- ret_units
If set to TRUE the value(s) returned are of class

`units`

with units attached to the value. [Default is FALSE]

## Value

rho, the density of water for the dens function [\({kg}\,{m^{-3}}\) or \({slug}\,{ft^{-3}}\)]

spwt, the specific weight of water for the specwt function [\({N}\,{m^{-3}}\) or \({lbf}\,{ft^{-3}}\)]

mu, the dynamic viscosity of water for the dvisc function [\({N}\,{s}\,{m^{-2}}\) or \({lbf}\,{s}\,{ft^{-2}}\)]

nu, the kinematic viscosity of water for the kvisc function [\(m^2 s^{-1}\) or \(ft^2 s^{-1}\)].

svp, the saturation vapor pressure of water for the svp function [\(N m^{-2}\) or \(lbf ft^{-2}\)].

surf_tension, the surface tension of water for the surf_tension function [\(N m^{-1}\) or \(lbf ft^{-1}\)].

Ev, the bulk modulus of elasticity of water for the Ev function [\(N m^{-2}\) or \(lbf ft^{-2}\)].

## Examples

```
#Find kinematic viscocity for water temperature of 55 F
nu = kvisc(T = 55, units = 'Eng')
#Find kinematic viscocity assuming default water temperature of 68 F
nu = kvisc(units = 'Eng')
#>
#> Temperature not given.
#> Assuming T = 68 F
#Find water density for water temperature of 25 C
rho = dens(T = 25, units = 'SI')
#Find saturation vapor pressure for water temperature of 10 C
vps = svp(T = 10, units = 'SI')
#Find surface tension for water temperature of 10 C
s_tens = surf_tension(T = 10, units = 'SI')
```