Isothermal Liquid Predefined Properties (IL)

You can configure the block to simulate the properties of several different predefined liquids using the parameter Isothermal liquid.

Voda

The unit provides water properties in the range between the triple point, when the temperature and pressure of the liquid reach 273.160 To and 611.657 Pa, and the critical point when the temperature of the liquid reaches 647.096 K. Value It is set by the pressure at the triple point or the saturation pressure, whichever is greater.

Mixtures of ethylene, propylene and glycerin with water_

The block provides properties for ethylene glycol, propylene glycol, and glycerol at temperatures above the freezing point of the solution.

When setting the mixture, you can determine the concentration of ethylene glycol, propylene glycol, or glycerol in water by mass or volume fraction using the parameter Concentration type.

The block provides properties for:

The block stores properties as a function of temperature and concentration. The unit retains all properties except for density and coefficient of thermal expansion. , as constants for the pressure range.

_ Sea water_

The block provides properties for seawater for temperatures from 273.15 To before 393.15 K and pressures above the saturation pressure in the system. The salt concentration may vary from 0 before 0.12 by weight.

The block stores properties in tabular form depending on pressure and temperature.

The data for the block is obtained from the software on the website https://web.mit.edu/seawater/.

Jet-A Aviation Fuel_

The unit provides properties for a common, representative fuel mixture based on Jet-A-4658 and Jet-A-3638 substitutes at temperatures from 222.22 To before 645.61 K and pressures above the saturation point.

The unit stores the characteristics in tabular form depending on pressure and temperature.

diesel fuel

The block provides properties for diesel fuel at temperatures from 238.20 To before 690.97 K and pressures above the saturation point.

SAE 5W-30

The block provides properties for SAE 5W-30 at temperatures from 235.15 To before 473.15 To and pressures above 0.01 MPa. The block determines the properties based on the values of the system temperature and atmospheric pressure for temperatures from 29.85 °C to 74.85 °C (from 303 K before 348 K) and pressures from 7 MPa up to 87 MPa. The block uses curve approximation to determine properties in extrapolated regions.

_ Lubricating oils and hydraulic fluids_

The block uses numerical approximations to calculate the properties of the following liquids:

The block uses the Walter equation to approximate velocity changes. depending on the temperature :

where , and — constants specific to each liquid.

The block assumes that the density of it varies linearly depending on the temperature:

where

Volumetric modulus of elasticity defined as

where — the speed of sound. The block uses the value for the speed of sound in hydraulic oils 1460 m/s.

benzine

The unit uses the same approximations as for lubricating oils and hydraulic fluids to calculate the density and volumetric modulus of elasticity of gasoline. In gasoline, the speed of sound is 1250 m/s.

The viscosity of gasoline is calculated using the Vogel—Fulcher—Tamman equation.:

where , and — constants.

In the block, you can simulate the dissolution of air in a liquid system. If you check the box Model air dissolution, then the block simulates dissolution in the pressure range, which is determined by the values of the parameters Atmospheric pressure and Pressure at which all entrained air is dissolved using Henry’s law.