R/fooOth.R

Defines functions Vp CT BT pMeltT hps Dps Tps Dhs Ths DTs sph Dph Tph DTh TDh TDs TDp

Documented in BT CT Dhs Dph Dps DTh DTs hps pMeltT sph TDh TDp TDs Ths Tph Tps Vp

#' Temperature, Function of Density and Pressure
#'
#' @description The function \code{TDp(D,p,digits=9)} returns the water temperature, Temp [ K ],
#'      for given D [kg/m3] and p [ MPa ].
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param D Density [ kg m3 ]
#' @param p Pressure [ MPa ]
#' @param digits Digits of results (optional)
#' 
#' @return The Temperature: Temp [ K ] and an Error Message (if an error occur: \link{errorCodes})
#' 
#' @examples
#' D <- 838.025
#' p <- 10.0003858
#' T_Dp <- TDp(D,p)
#' T_Dp
#' 
#' @export
#' 
  TDp <- function(D,p,digits=9) {
    y <- 0.
  icode <- 0
  res <- .Fortran('TDp', as.double(D), as.double(p), as.double(y), as.integer(icode))
  if (res[[4]] != 0) { 
     error <-  as.character(errorCodes[which(errorCodes[,1]==res[[4]]),2])
     print(error)
  }
  out <- round(res[[3]],digits)
  return(out)
  }

#' Temperature, Function of Density and Entropy
#'
#' @description The function \code{TDs(D,s,digits=9)} returns the water temperature, Temp [ K ],
#'      for given D [kg/m3] and s [ kJ kg-1 K-1 ].
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param D Density [ kg m3 ]
#' @param s Entropy in [ kJ kg-1 K-1 ]
#' @param digits Digits of results (optional)
#' 
#' @return The Temperature: Temp [ K ] and an Error Message (if an error occur: \link{errorCodes})
#' 
#' @examples
#' D <- 838.025
#' s <- 2.56690919
#' T_Ds <- TDs(D,s)
#' T_Ds
#' 
#' @export
#' 
TDs <- function(D,s,digits=9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('TDs', as.double(D), as.double(s), as.double(y), as.integer(icode))
  if (res[[4]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[4]]),2])
    print(error)
  }
  out <- round(res[[3]],digits)
  return(out)
}

#' Temperature, Function of Density and Enthalpy
#'
#' @description The function \code{TDh(D,h,digits=9)} returns the water temperature, Temp [ K ],
#'      for given D [kg/m3] and h [ kJ kg-1 ].
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param D Density [ kg m3 ]
#' @param h Enthaly in [ kJ kg-1 ]
#' @param digits Digits of results (optional)
#' 
#' @return The Temperature: Temp [ K ] and an Error Message (if an error occur: \link{errorCodes})
#' 
#' @examples
#' D <- 838.025
#' h <- 977.181624
#' T_Dh <- TDh(D,h)
#' T_Dh
#' 
#' @export
#' 
TDh <- function(D,h,digits=9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('TDh', as.double(D), as.double(h), as.double(y), as.integer(icode))
  if (res[[4]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[4]]),2])
    print(error)
  }
  out <- round(res[[3]],digits)
  return(out)
}

#' Density, Function of Temperature and Enthalpy
#'
#' @description The function \code{DTh(Temp,h,digits=9)} returns the water density, D [ kg m-3 ],
#'      for given Temp [K] and h [ kJ kg-1 ] (it may have two solutions for Density).
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param Temp Temperature in Kelvin
#' @param h Enthalpy in [ kJ kg-1 ]
#' @param digits Digits of results (optional)
#' 
#' @return The Density 1: Density_1 [ kg m-3 ]
#' @return The Density 2: Density_2 [ kg m-3 ]
#' @return Error Message (if an error occur: \link{errorCodes})
#' 
#' @examples
#' Temp <- 500.
#' h <- 977.181624
#' D_Th <- DTh(Temp,h)
#' D_Th
#' 
#' @export
#' 
DTh <- function(Temp,h,digits = 9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('DTh', as.double(Temp), as.double(h), as.double(y), as.double(y), as.integer(icode))
  out <- list(Density_1=round(res[[3]],digits), Density_2=round(res[[4]],digits))
  if (res[[5]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[5]]),2])
    print(error)
  }
  return(out)
}

#' Temperature, Function of Pressure and Enthalpy
#' 
#' @description The function \code{Tph(p,h,digits = 9)} returns the water temperature, Temp [ K ],
#'      for given p [MPa] and h [ kJ k-1 ].
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param p Pressure [ MPa ]
#' @param h Enthalpy [ kJ kg-1 ]
#' @param digits Digits of results (optional)
#' 
#' @return The Temperature: Temp [ K ] and an Error Message (if an error occur: \link{errorCodes})
#' 
#' @examples
#' p <- 10.0003858
#' h <- 977.181624
#' T_ph <- Tph(p,h)
#' T_ph
#' 
#' @export
#' 
Tph <- function(p,h,digits =9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('Tph', as.double(p), as.double(h), as.double(y), as.integer(icode))
  if (res[[4]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[4]]),2])
    print(error)
  }
  out <- round(res[[3]],digits)
  return(out)
}

#' Density, Function of Pressure and Enthalpy
#'
#' @description The function \code{Dph(p,h,digits=9)} returns the water density, D [ kg m-3 ],
#'      for given p [MPa] and h [ kJ k-1 ].
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param p Pressure [ MPa ]
#' @param h Enthalpy [ kJ kg-1 ]
#' @param digits Digits of results (optional)
#' 
#' @return The Density: D [ kg m-3 ] and an Error Message (if an error occur: \link{errorCodes})
#' 
#' @examples
#' p <- 10.0003858
#' h <- 977.181624
#' D_ph <- Dph(p,h)
#' D_ph
#' 
#' @export
#' 
Dph <- function(p,h,digits=9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('Dph', as.double(p), as.double(h), as.double(y), as.integer(icode))
  if (res[[4]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[4]]),2])
  }
  out <- round(res[[3]],digits)
  return(out)
}

#' Entropy, Function of Pressure and Enthalpy
#'
#' @description The function \code{sph(p,h,digits=9)} returns the water entropy, s [ kJ kg-1 K-1 ],
#'      for given p [MPa] and h [ kJ k-1 ].
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param p Pressure [ MPa ]
#' @param h Enthalpy [ kJ kg-1 ]
#' @param digits Digits of results (optional)
#' 
#' @return The Entropy: s [ kJ kg-1 K-1 ] and an Error Message (if an error occur: \link{errorCodes})
#' 
#' @examples
#' p <- 10.0003858
#' h <- 977.181624
#' s_ph <- sph(p,h)
#' s_ph
#' 
#' @export
#' 
sph <- function(p,h,digits = 9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('sph', as.double(p), as.double(h), as.double(y), as.integer(icode))
  if (res[[4]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[4]]),2])
    print(error)
  }
  return(round(res[[3]],digits = digits))
}

#' Density, Function of Temperature and Entropy
#'
#' @description The function \code{DTs(Temp,s,digits=9)} returns the water density, D [ kg m-3 ],
#'      for given Temp [K] and s [ kJ k-1 K-1 ].
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param Temp Temperature [ K ]
#' @param s Entropy [ kJ kg-1 K-1 ]
#' @param digits Digits of results (optional)
#' 
#' @return The Density: D [ kg m-3 ] and an Error Message (if an error occur: \link{errorCodes})
#' 
#' @examples
#' Temp <- 500.
#' s <- 2.56690919
#' D_Ts <- DTs(Temp,s)
#' D_Ts
#' 
#' @export
#' 
#' @export
#' 
DTs <- function(Temp,s,digits=9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('DTs', as.double(Temp), as.double(s), as.double(y), as.integer(icode))
  if (res[[4]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[4]]),2])
    print(error)
  }
  return(round(res[[3]],digits=digits))
}

#' Temperature, Function of Enthalpy and Entropy
#'
#' @description The function \code{Ths(h,s,digits=9)} returns the water Temperature, Temp [ K ],
#'      for given h [kJ k-1] and s [ kJ k-1 K-1 ].
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param h Enthalpy [ kJ kg-1 ]
#' @param s Entropy [ kJ kg-1 K-1 ]
#' @param digits Digits of results (optional)
#' 
#' @return The Temperature: Temp [ K ] and an Error Message (if an error occur: \link{errorCodes})
#' 
#' @examples
#' h <- 977.181624
#' s <- 2.56690919
#' T_hs <- Ths(h,s)
#' T_hs
#' 
#' @export
#' 
Ths <- function(h,s,digits=9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('Ths', as.double(h), as.double(s), as.double(y), as.integer(icode))
  if (res[[4]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[4]]),2])
    print(error)
  }
  return(round(res[[3]],digits=digits))
}

#' Density, Function of Enthalpy and Entropy
#'
#' @description The function \code{Dhs(h,s,digits=9)} returns the water density, D [ kg m-3 ],
#'      for given h [kJ k-1] and s [ kJ k-1 K-1 ].
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param h Enthalpy [ kJ kg-1 ]
#' @param s Entropy [ kJ kg-1 K-1 ]
#' @param digits Digits of results (optional)
#' 
#' @return The Density: D [ kg m-3 ] and an Error Message (if an error occur: \link{errorCodes})
#' 
#' @examples
#' h <- 977.181624
#' s <- 2.56690919
#' D_hs <- Dhs(h,s)
#' D_hs
#' 
#' @export
#' 
Dhs <- function(h,s,digits=9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('Dhs', as.double(h), as.double(s), as.double(y), as.integer(icode))
  if (res[[4]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[4]]),2])
    print(error)
  }
  return(round(res[[3]],digits=digits))
}

#' Temperature, Function of Pressure and Entropy
#'
#' @description The function \code{Tps(p,s,digits=9)} returns the water temperature, Temp [ K ],
#'      for given p [MPa] and s [ kJ k-1 K-1 ].
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param p Pressure [ MPa ]
#' @param s Entropy [ kJ kg-1 K-1 ]
#' @param digits Digits of results (optional)
#' 
#' @return The Temperature: Temp [ K ] and an Error Message (if an error occur: \link{errorCodes})
#' 
#' @examples
#' p <- 10.0003858
#' s <- 2.56690919
#' T_ps <- Tps(p,s)
#' T_ps
#' 
#' @export
#' 
Tps <- function(p,s,digits=9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('Tps', as.double(p), as.double(s), as.double(y), as.integer(icode))
  if (res[[4]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[4]]),2])
    print(error)
  }
  return(round(res[[3]],digits=digits))
}

#' Density, Function of Pressure and Entropy
#'
#' @description The function \code{Dps(p,s,digits=9)} returns the water density, D [ kg m-3 ],
#'      for given p [MPa] and s [ kJ k-1 K-1 ].
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param p Pressure [ MPa ]
#' @param s Entropy [ kJ kg-1 K-1 ]
#' @param digits Digits of results (optional)
#' 
#' @return The Density: D [ kg m-3 ] and an Error Message (if an error occur: \link{errorCodes})
#' 
#' @examples
#' p <- 10.0003858
#' s <- 2.56690919
#' D_ps <- Dps(p,s)
#' D_ps
#' 
#' @export
#' 
Dps <- function(p,s,digits=9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('Dps', as.double(p), as.double(s), as.double(y), as.integer(icode))
  if (res[[4]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[4]]),2])
    print(error)
  }
  return(round(res[[3]],digits))
}

#' Enthalpy, Function of Pressure and Entropy
#'
#' @description The function \code{hps(p,s,digits=9)} returns the water enthalpy, h [ kJ kg-1 ],
#'      for given p [MPa] and s [ kJ k-1 K-1 ].
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param p Pressure [ MPa ]
#' @param s Entropy [ kJ kg-1 K-1 ]
#' @param digits Digits of results (optional)
#' 
#' @return The Enthalpy: h [ kJ kg-1 ] and an Error Message (if an error occur: \link{errorCodes})
#' 
#' @examples
#' p <- 10.0003858
#' s <- 2.56690919
#' h_ps <- hps(p,s)
#' h_ps
#' 
#' @export
#' 
hps <- function(p,s,digits=9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('hps', as.double(p), as.double(s), as.double(y), as.integer(icode))
  if (res[[4]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[4]]),2])
    print(error)
  }
  return(round(res[[3]],digits))
}

#' Melting Pressure, Function of Temperature
#'
#' @description The function \code{pMeltT(Temp,digits=9)} returns the water melting pressure,
#'      pMelt [ MPa ], for a given Temp [K].
#'
#' @details This function calls a Fortran DLL that solves the equations given at the
#'      Revised Release on the Pressure along the Melting and Sublimation Curves of
#'      Ordinary Water Substance (September 2011), developed by the International 
#'      Association for the Properties of Water and Steam, 
#'      \url{http://www.iapws.org/relguide/MeltSub.html}. It is valid from the 
#'      Temperature of 256.164 [K] to the Temperature of 715 [K].
#'     
#' @param Temp Temperature [K]
#' @param digits Digits of results (optional)
#' 
#' @return The melting pressure: pMelt [ MPa ] for regions III, V , VI and VII
#' @return The melting pressure: pMeltIh [ MPa ] for region Ih
#' @return The sublimation pressure: pSubl [ MPa ], below triple point Temperature
#' @return Error message (if an error occur)
#' 
#' @examples
#' Temp <- 275.
#' p_Melt <- pMeltT(Temp)
#' p_Melt
#' 
#' @export
#' 
pMeltT <- function(Temp,digits=9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('pMeltT', as.double(Temp), as.double(y), as.double(y), as.double(y), as.integer(icode))
  out <- list(Temperature=Temp, pMelt=round(res[[2]],digits), pMeltIh=round(res[[3]],digits), pSubl=round(res[[4]],digits))
  if (res[[5]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[5]]),2])
    print(error)
  }
  return(out)
}

#' Second Virial Coefficient (B), Function of Temperature
#'
#' @description The function \code{BT(Temp,digits=9)} returns the second virial coefficient,
#'      B [ m3 kg-1 ], for a given T [K].
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param Temp Temperature [K]
#' @param digits Digits of results (optional)
#' 
#' @return The second virial coefficient: B [ m3 kg-1 ] and an Error Message 
#'     (if an error occur: \link{errorCodes})
#' 
#' @examples
#' Temp <- 500.
#' B_T <- BT(Temp)
#' B_T
#' 
#' @export
#' 
  BT <- function(Temp,digits=9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('BT', as.double(Temp), as.double(y), as.integer(icode))
  if (res[[3]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[3]]),2])
    print(error)
  }
  out <- round(res[[2]],digits)
  return(out)
}

#' Third Virial Coefficient (C), Function of Temperature
#'
#' @description The function \code{CT(Temp,digits=9)} returns the third virial coefficient,
#'      C [ m3 kg-1 ]**2, for a given Temp [K].
#'
#' @details This function calls a Fortran DLL that solves the Helmholtz Energy Equation. 
#'     in accordance with the Revised Release on the IAPWS Formulation 1995 for the 
#'     Thermodynamic Properties of Ordinary Water Substance for General and Scientific
#'     Use (June 2014) developed by the International Association for the Properties of
#'     Water and Steam,  \url{http://www.iapws.org/relguide/IAPWS-95.html}. It is valid  
#'     from the triple point to the pressure of 1000 MPa and temperature of 1273.
#'     
#' @param Temp Temperature [K]
#' @param digits Digits of results (optional)
#' 
#' @return The second virial coefficient: C [ m3 kg-1 ]**2 and an Error Message 
#'     (if an error occur: \link{errorCodes})
#' 
#' @examples
#' Temp <- 500.
#' C_T <- CT(Temp)
#' C_T
#' 
#' @export
#' 
CT <- function(Temp,digits=9) {
  y <- 0.
  icode <- 0
  res <- .Fortran('CT', as.double(Temp), as.double(y), as.integer(icode))
  if (res[[3]] != 0) { 
    error <-  as.character(errorCodes[which(errorCodes[,1]==res[[3]]),2])
    print(error)
  }
  out <- round(res[[2]],digits)
  return(out)
}
#' Vapor pressure, Function of Temperature
#'
#' @description The function \code{Vp(Temp,digits=9)} returns the vapor pressure,
#'      Vp [ kPa ], for a given Temp [K]. 
#'
#' @details This function solves the Wagner Equation (Wagner and Pruss (1993))
#'      which gives one of the best fits to experimental data. It expresses reduced
#'      vapor pressure as a function of reduced temperature. This equation, for water,
#'      is valid from the temperature of 273.16 K to the critical temperature (624.096 K).
#'     
#' @param Temp Temperature [K]
#' @param digits Digits of results (optional)
#' 
Vp <- function(Temp,digits=9) {
 # pCrit <- as.double(22.064): Critical Pressure
 # TCrit <- as.double(647.096): Critical Temperature

  TL <- 273.16  # Lower temperature limit
  TH <- 647.096 # Upper temperature limit
  if ( (Temp < TL) | (Temp > TH) ) { 
    print("Temperature out of bounds")
  }
  
 Tc1 <- 0.001545365757 # 1./Tc
 Tr = T*Tc1 # T/Tc
 Pc <- 22064. # kPa
 
 a1 <- -7.85951783
 a2 <- 1.84408259
 a3 <- -11.7866497
 a4 <- 22.6807411 
 a5 <- -15.9618719
 a6 <- 1.80122502
 tal <- 1.-Tr
 
 lnPr <- (a1*tal + a2*(tal^1.5) + a3*(tal^3) + a4*(tal^3.5) + a5*(tal^4) + a6*(tal^7.5))/Tr
 
 Pr <- exp(lnPr)
 Vp <- Pc * Pr
 out <- round(Vp,digits)
return(out)

 }

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IAPWS95 documentation built on June 24, 2022, 9:05 a.m.