R/vapour_pressure.R

In ratral/hyd4gpv: General Purpose Valve functions

#' @title Vapour pressure of water
#' @description The vapor pressure of water is the pressure at which water vapor is in
#' thermodynamic equilibrium with its condensed state. At higher pressures water
#' would condense. The water vapor pressure is the partial pressure of water
#' vapor in any gas mixture in equilibrium with solid or liquid water.
#' As for other substances, water vapor pressure is a function of temperature
#' and can be determined with the Clausius–Clapeyron relation.
#' Approximation formula :
#' The Buck equation. where T is in °C and P is in kPa.
#' https://en.wikipedia.org/wiki/Vapour_pressure_of_water
#' @author Dr. Raúl Trujillo Álvarez
#' @param temp is in °C
#' @return Vapour pressure of water in (bar)
#' @export
#' @examples
#' vapour_pressure(25)
#'
#'@section Last Updated By:
#'Dr. Trujillo
#'
#'@section Last Update Date:
#'2021/10/24

vapour_pressure <- function(temp = 20){
  pv <- 0.61121*exp((18.678-temp/234.5)*(temp/(257.14+temp)))
  return(pv/100)
}