1. Bases models.

                                                                A Main thesis:

             Near Bottom of vapour-gas channel inheres spot of zero velocity hydrodynamic

                                                              motion - a spot 0. (Pic.1-4)

                                                               An Effect of thesis:

                   1)From constancies on current lines of a value =B,
 o than states a law Bernoulli (here  - density of liquid, g -constant free  falling,
h -a depth under the surface of water v - velocity, W - a heat function units of volume )
follows that in this spot 0: B=(W - gh) . If consider a motion an isoentropy,
 W = P / , where P -a pressure of liquid, and then, as far as pass near spots 0
current lines:

                                    a) go out on surface of liquid and

                                    b) with small velocity (nearly surfaces of current line

have a rarefaction),possible  take :                                       (1)

 where P - an atmospheric pressure, h - a depth of channel, close depth of flooding a spot
0 - a zero velocity of moving a liquid, P - a pressure of liquid just subon the bottom
of channel.

                                Consequence:                                   (1" )

                        2 Since experimental values h = 1cm , this signifies that
process of evaporation in vapour-gas channel occurs under the atmospheric pressure
practically. Really, condition of the balance position of bottom of channel in rough
drawing near is defined by equality near it

pressures in fluid phase    and in gas phase   pressure pair on the day of
 channel. Then swing of pressures between bottom of channel and atmosphere

 pproximately is -   g h , but its relative value:


                                    An Equation on the depth of channel.

   Position of bottom of channel will be assign by the condition of balance of power on
the part of liquids and on the part of the gas. In this balance necessary to take into
               b)form borders of section,
               c)variation of density of flow of pulse through the border of section(Pic.4).


On first effect from main thesis models a pressure on the part of liquids
Pressure a pair on bottom of channel will be assign by temperature
liquids on the border:

Here  - a pressure saturated pair at the temperature T. For evaluations near 100°C with follows to use a correlation:


 where ST- an overheat on the border a liquid - a vapour(Pic4).

                                                    b) A form of borders of section.

   As is well known , border of section in form of half-spheres creates additional pressure inwardly, where   - a factor shallow stretching borders (    = 58 Din\cm under T=100°C) , R - a radius of half-sphere(Pic.4).

                            c)Variation of flow of pulse under phase transition.

   Density of flow of pulse is J´V, where J - a flow of mass with units of area J = q´V ,( q - density,
V - a velocity).
As far as under phase transition a mass is not changed -,i.e. mass flows of liquid reduce co to the bottom a channel and pair in the most channel near bottom alike. Changing density of flow of pulse , answer pressure of return vaporize pair, will form
where   - density saturated water pair, - its velocity on day channel,  - density of

water, - a velocity of supply of liquid co to the bottom.

   Value density saturated water pair under atmospheric pressure From equation of condition a pair, considered as ideal gas,, where  m - a mass of molecule of water, k - constant of Bolzman, T - a temperature.
That gives:


                      Tables and the numerical values take from reference books.
                      Underlining by the wavy line means (indicates) statement,
                      which are to be more carefully motivated in purposes
                      of evaluation of borders of aplicability.