R/sigma_i.R

In ratral/hyd4gpv: General Purpose Valve functions

#' @title Incipient Cavitation.
#' @description The onset of cavitation, where only small vapor bubbles are
#' formed in the flow stream. A cavitation level sufficient to begin minor,
#' observable indications of pitting damage.
#'  - Onset of cavitation;
#'  - Detect using high-frequency vibration measurement;
#'  - Very local phenomenon; Transient: random “ticks” sound;
#'  - Low-level cavitation: usually not damaging;
#'  - Occurs prior to the loss of capacity
#'
#' @param fls liquid pressure recovery full open (max between fl and Flp/Fp)
#' @param x valve position
#' @param b steepness
#' @param d upper value
#' @param e the effective dose
#'
#' @return Sigma_i
#' @export
#'
sigma_i <- function(x, b, d, e, fls){
  xfz <- 0.71
  kv_kvs <- drm_LL3(x, b, d, e)
  return( (1/(xfz * fls^2) - 1) * kv_kvs)
}