=Paper= {{Paper |id=Vol-2407/paper-08-172 |storemode=property |title= Numerical solution of the problem of homogeneous nucleation in the liquid phase |pdfUrl=https://ceur-ws.org/Vol-2407/paper-08-172.pdf |volume=Vol-2407 |authors=Nickolay Yu. Kravchenko,Dmitry S. Kulyabov |dblpUrl=https://dblp.org/rec/conf/ittmm/KravchenkoK19 }} == Numerical solution of the problem of homogeneous nucleation in the liquid phase == https://ceur-ws.org/Vol-2407/paper-08-172.pdf
74


UDC 519.63
 Numerical solution of the problem of homogeneous nucleation
                      in the liquid phase
                 Nickolay Yu. Kravchenko* , Dmitry S. Kulyabov†
                      *
                        Institute of Physical Research and Technology
               Peoples’ Friendship University of Russia (RUDN University)
               6 Miklukho-Maklaya St, Moscow, 117198, Russian Federation
                   †
                     Department of Applied Probability and Informatics
               Peoples’ Friendship University of Russia (RUDN University)
               6 Miklukho-Maklaya St, Moscow, 117198, Russian Federation
                          ‡
                            Laboratory of Information Technologies
                             Joint Institute for Nuclear Research
                  6 Joliot-Curie, Dubna, Moscow region, 141980, Russia
                         Email: kravchenko-nyu@rudn.ru, kulyabov-ds@rudn.ru

   The paper considers the processes taking place in the liquid phase: nucleation in liquids
and liquid metals, electrical explosion of conductors and spark cavitation. It is established
that all these processes are well described by the basic equation of cavitation, which is
solved numerically by the Runge–Kutta method. For this purpose, a program in the Fortran
programming language has been created, and a method for determining the time of appearance
of cavitation nuclei by the method of numerical integration has been described. A mathematical
model of homogeneous nucleation in the liquid phase was created. With the help of the
created model, such parameters as the time of appearance of a cavitation bubble for various
frequencies of external influence were calculated. The maximum amplitude and period of the
natural oscillations of a bubble at various frequencies.

    Key words and phrases: numerical solution, cavitation, mathematical model of cavita-
tion, spark cavitation, liquid metals.




Copyright © 2019 for the individual papers by the papers’ authors. Copying permitted for private and
academic purposes. This volume is published and copyrighted by its editors.
In: K. E. Samouylov, L. A. Sevastianov, D. S. Kulyabov (eds.): Selected Papers of the IX Conference
“Information and Telecommunication Technologies and Mathematical Modeling of High-Tech Systems”,
Moscow, Russia, 19-Apr-2019, published at http://ceur-ws.org
                               Kravchenko N. Y., Kulyabov D. S.                         75


                                  1.   Fluid nucleation
    The theory of thermodynamic stability was developed by Gibbs in the last century.
Thermodynamic stability of a system is understood as the equilibrium of a system of
relatively small changes in its thermodynamic parameters, such as volume, pressure,
temperature, etc. For thermodynamic equilibrium of a system, it is necessary that its
internal energy be minimal. The condition of the positivity of the value of the second
derivative of the internal energy [1] follows from the requirement of a minimum of
internal energy. It, in turn, leads to a number of thermodynamic inequalities, which are
the conditions of thermodynamic stability.
    The boundary of the thermodynamic stability of the phase is the spinodal. The
position of the spinodal can be calculated from the thermal equation of state for liquids
and gases, the simplest of which is the Van der Waals equation. Spinodal consists
of two branches: steam and liquid. The spinodal of the vapor phase determines the
vapor saturation limit. The spinodal of the liquid phase determines the boundary of the
thermodynamic stability of the liquid [2], [3]. With a positive pressure - the limiting
temperature of the liquid overheating, with a negative pressure (tension) - the ultimate
tensile strength of the liquid.
    Between the binodal (line of phase equilibrium) and the spinodal of the liquid phase
lies the region of the metastable liquid, overheated or stretched. From the point of view
of thermodynamics, a superheated liquid is essentially no different from a stretched one.
    In the region of a metastable liquid, cavities filled with steam, gas, or their mixture
(cavities) appear in the process of heating a liquid at constant pressure or in the process
of decreasing pressure at a constant temperature.
    The process of the formation and development of bubbles depends on the state of the
liquid, including the presence of solid or gaseous impurities in it, and on the pressure in
the liquid.
    Thus, for nucleation in a liquid it must be stretched to a certain pressure, not
exceeding in absolute value the limits of the thermodynamic stability [4] of the liquid
(spinodal).

                          2.    Nucleation in liquid metals
    The theory of nucleation was proposed in the works of V.P. Skripov and students [5],
[6], [7].
    Later it was shown that the implementation of unstable states is also possible for
liquid metals, which follows from experiments with an electric explosion of conductors [8].
In the process of such an electric explosion, an emission of X-rays and multiply charged
ions was detected. This is explained by the fact that in the process of the spinodal
decomposition of the unstable liquid metal phase, regions with a sharp local temperature
rise appear, which leads to thermal excitation of atoms and electronic transitions that
generate X-ray quantums. The presence of such local “hot centers” with an “anomalous”
electrical explosion of conductors is confirmed by the release of multiply charged ions
from the explosion zone [9], [10]. The output of short-wave X-ray quantums with an
electric explosion of titanium and iron was detected in [11].
    Overheating cannot be arbitrarily large, since there is a boundary between the
thermodynamic stability of the phase and the spinodal. When approaching the spinodal,
the fluctuation mechanism of nucleation or homogeneous nucleation comes into play,
which ensures the rapid disintegration of the metastable phase [12]. The process of
homogeneous nucleation manifests itself most vividly when the liquid phase is pulsed,
which is expressed in the explosive boiling up of the liquid phase that is superheated to
the vicinity of the spinodal. Such an explosion also occurs after the release of pressure
from a fluid that has been preheated under pressure to a temperature close to the critical
one.
76                                                                             ITTMM—2019


                      3.   Electrical explosion of conductors
    Experiments have shown [8] that overheating of the liquid metal to the vicinity of
the spinodal is possible when the metal conductors are heated by a microsecond current
pulse. With this heat, the mass of metal evaporated through the surface the conductor
and through the surface of vapor nuclei arising on the ready-made centers is insignificant,
so the conductor remains in a liquid state up to the vicinity of the spinodal.
    Overheating of a thermodynamically stable liquid above the spinodal point is im-
possible, since when approaching this point, an explosive boiling mechanism comes into
play, caused by a high frequency of homogeneous nucleation of vapor nuclei.
    The calculation shows that when approaching the spinodal, the frequency of homo-
geneous nucleation increases by 28 orders of magnitude, which ensures the explosive
boiling of the superheated liquid metal. This process is the main factor determining the
electrical explosion of conductors when they are heated by a microsecond current pulse.

                                 4.   Spark cavitation
    This phenomenon is observed in a vacuum diode with a cathode in the form of an
edge and a flat anode. When a voltage pulse is applied to the diode, electrons are ejected
from the tip through a tunneling mechanism; this phenomenon is called field emission.
As the voltage pulse increases, the autoelectronic current increases and, when its density
reaches a certain limit value, the tip of the tip explodes, which leads to an increase in
the emission current 10 - 100 times. The process of microexplosions can be repeated
many times, so as after the explosion of this tip, new microprotrusions are formed on
the cathode.
    The electrical explosion mechanism of the tip is similar to the electrical explosion of
conductors; it is determined by the phase explosion of the superheated liquid metal [13],
[14].
    In the case of an explosion of the edges, the probability of reaching unstable states
of the liquid phase and its spinodal decomposition is greater than with the explosion of
conductors.
    A shock wave arises in the liquid, and a cavity filled with metal vapor forms around
the microprotrusion. The cavity expands to a maximum radius, after which it makes
damped oscillations. With each compression of the cavity, the gas contained in it
is heated. Such a mechanism for the development of the spark cavitation process is
confirmed by experimental studies.
    Thus, if the developed interpretation of the observed effect in the process of spark
cavitation is fair, then with spherical cumulation of a sufficiently strong shock wave in
the center of the spherical cavity in a certain short period of time, we should expect the
realization of the extreme state of matter [15], [16].

           5.   The mathematical model of homogeneous nucleation
    It can be said that all the processes described above, namely nucleation in liquids and
in liquid metals, electrical conductor explosion and spark cavitation can be represented
by the same model of homogeneous nucleation in the liquid phase.
    We have created a mathematical model of homogeneous nucleation in the liquid
phase. It applies to all the processes described here and has already been used by us in
the case of spark cavitation [17].
    The model is built on the basis of an equation describing the dynamics of a cavitation
bubble:
                                [︃(︂                                         ]︃
                                                  𝑅0 3𝛾
                                            )︂ (︂   )︂
              ¨ + 3 𝑅˙ 2 = 1
              𝑅𝑅                    𝑝𝑜 +
                                         2𝜎
                                                        −
                                                          2𝜎
                                                             − 𝑝0 + 𝑝(𝑡, 𝑡1 ) ,          (1)
                     2        𝜌          𝑅0       𝑅        𝑅
   Here: 𝑅0 - radius of the nucleus at 𝑡 = 0; 𝑅 -radius of the nucleus at the next time
instant 𝑡; 𝜌 -density of a liquid; 𝜎 - surface tension of the fluid; 𝑘 = 1 - adiabatic index
                                     Kravchenko N. Y., Kulyabov D. S.                                          77


for steam in the bud; 𝑝𝑜 - hydrostatic pressure in a liquid (𝑝𝑜 = 𝑝𝑏 ); 𝑅
                                                                        ¨ - acceleration of
the cavity wall; 𝑅˙ is the speed of movement of the cavity wall; 𝑅 2𝜎
                                                                       - Laplace pressure;
                                                                                      0
𝑅0
𝑅
    - amplitude of oscillations of the cavity, 𝑡1 − the time of appearance of the first germ
of homogeneous cavitation.
   Time 𝑡1 is determined from the condition
                                              ∫︁𝑡1         (︂        )︂
                                                                𝐶
                                         𝐵·          exp                  𝑑𝑡 = 1.                             (2)
                                                                𝑡2
                                              0

    Taking into account the geometric meaning of a definite integral (2), one can determine
the point 𝑡1 , by numerical method knowing that the area of the figure bounded by the
function 𝑓 (𝑥) on the interval [0, 𝑡1 ] should be equal to 1.
    Part of the program of numerical integration for finding the time 𝑡1 is given below
(see Listing 1). The program is written in a programming language Fortran.

  Listing 1: Program for the numerical determination of the stretching time 𝑡1
   print ∗ , ’ ’
   print ∗ , ’ The␣ program ␣ i s ␣ d e s i g n e d ␣ t o ␣ c a l c u l a t e : ’
   print ∗ , ’============================’
   print ∗ , ’ 1 ) ␣ a m p l i t u d e ␣ o f ␣ a c o u s t i c ␣ p r e s s u r e ␣P1␣ a t ␣ t h e ␣
        ˓→ p o i n t ␣ o f ␣ a p p e a r a n c e ␣ o f ␣ one ␣ germ ␣ c a v i t a t i o n ␣ based ␣ on ␣
        ˓→ t h e ␣ t h e o r y ␣ o f ␣V. P . ␣ S k r i p o v ; ␣ ’
   print ∗ , ’ 2 ) ␣ t h e ␣ d u r a t i o n ␣ o f ␣ t h e ␣ e x e r c i s e ␣ o f ␣ t 1 ␣ u n t i l ␣ t h e ␣
        ˓→ a p p e a r a n c e ␣ o f ␣ a ␣ s i n g l e ␣ c a v i t a t i o n ␣ n u c l e u s ␣ ( a t ␣ p o i n t ␣
        ˓→ P1 ) ; ’
   print ∗ , ’ 3 ) ␣ Radius ␣ o f ␣ t h e ␣ c r i t i c a l ␣ embryo . ’
   print ∗ , ’ ’
   print ∗ , ’ t h e ␣ program ␣ w i l l ␣ not ␣ work ␣ w i t h o u t ␣ t h e ␣ data ␣ f i l e ␣
        ˓→ f o r ␣ t h e ␣ t e s t . ␣ s u b s t a n c e s ␣−␣ water ␣ 1 ␣ dat , ␣ a s ␣ w e l l ␣ a s ␣
        ˓→ w i t h o u t ␣ t h e ␣ s u p p o r t i n g ␣ f i l e ␣ a m p l i t . t x t . ␣ ’
   print ∗ , ’ ’
   print ∗ , ’ The␣ r e s u l t s ␣ o f ␣ t h e ␣ c a l c u l a t i o n s ␣ w i l l ␣ be ␣
        ˓→ d i s p l a y e d ␣ on ␣ t h e ␣ s c r e e n . ’
   open ( 1 , f i l e = ’ a m p l i t . t x t ’ )
   read ( 1 , ∗ ) aniu , amu , dt
   print ∗ , ’ ’
   print ∗ , ’ The␣ f o l l o w i n g ␣ p a r a m e t e r s ␣ a r e ␣ used ␣ i n ␣ t h e ␣ program : ’
   print ∗ , ’ ’
   print ∗ , ’ 1 ) ␣ E x t e r n a l ␣ f i e l d ␣ f r e q u e n c y ␣= ’ , aniu , ’ Hz ; ’
   print ∗ , ’ 2 ) ␣ Molar ␣ mass ␣ o f ␣ s u b s t a n c e ␣mu␣= ’ , amu , ’ kg ␣ / ␣ mol . ’
   print ∗ , ’ 3 ) ␣ I n t e g r a t i o n ␣ s t e p ␣ dt ␣= ’ , dt , ’ s ; ’
   print ∗ , ’ ’
   print ∗ , ’ I f ␣ you ␣ a r e ␣NOT␣ s a t i s f i e d ␣ with ␣ t h e s e ␣ p a r a m e t e r s , ␣
        ˓→ p r e s s ␣ " 1 " , ␣ then ␣ ’ Enter ’ , ␣ ’
   print ∗ , ’ i f ␣ s a t i s f i e d , ␣ p r e s s ␣ " 2 " , ␣ then ␣ " Enter " . ’
   print ∗ , ’ To␣ i n t e r r u p t ␣ a ␣ program , ␣ p r e s s ␣ " C t r l ␣+␣ c " . ’
   read ( ∗ , ∗ ) n
   i f ( n−1) 1 1 , 1 1 , 9
11 continue
   print ∗ , ’ Enter ␣ p a r a m e t e r s : ’
78                                                                                         ITTMM—2019


   print ∗ , ’ 1 ) ␣The␣ f r e q u e n c y ␣ o f ␣ t h e ␣ e x t e r n a l ␣ f i e l d ␣ ( Hz ) ; ’
   print ∗ , ’ 2 ) ␣ Molar ␣ mass ␣ o f ␣ s u b s t a n c e ␣mu␣ ( kg ␣ / ␣ mol ) ; ’
   print ∗ , ’ 3 ) ␣ I n t e g r a t i o n ␣ s t e p ␣ dt ␣ ( s ) . ’
   read ( ∗ , ∗ ) aniu , amu , dt
   close (1)
   open ( 2 , f i l e = ’ a m p l i t . t x t ’ )
   write ( 2 , ∗ ) aniu , amu , dt
9 continue
   open ( 3 , f i l e = ’ t1−r e s . dat ’ )
   open ( 4 , f i l e = ’ water −1. dat ’ )
   print ∗ , ’ ’
   write ( ∗ , ∗ ) ’T␣A␣B␣L␣ I ␣C␣A ’
   print ∗ , ’ ’
   write ( ∗ , ∗ ) ’ E x t e r n a l ␣ f i e l d ␣ f r e q u e n c y ␣= ’ , aniu , ’ Hz ’
   write ( ∗ , ∗ ) ’ t e m p e r a t u r e −time ␣ s t r e s s −p r e s s u r e −c r i t . ␣ r a d i u s ’
   write ( ∗ , ∗ ) ’T, ␣ g r a d e . ␣C−t1 , ␣mks−P1 , ␣MPa−Ro , ␣nm ’
   ak =1.3806581212 e −23
   ana =6.02213673636 e23
   p i =3.141592654
   w=2∗ p i ∗ a n i u
   expo =2.7182818284590459
1 continue
   read ( 4 , ∗ ) t t , s i g , r o l , rov , pb , pa
    i f ( tt ) 13 ,13 ,12
12 b=( r o l / r o v ) ∗ sqrt ( 2 ∗ s i g ∗ ana / (amu∗ p i ) )
   an=ana ∗ r o l /amu
   akk=an ∗ 1 . 0 e −06∗b
   a l =16∗ p i ∗ ( s i g ∗ ∗ 3 ) / ( 3 ∗ ak ∗ t t ∗(1− r o v / r o l ) ∗ ∗ 2 )
   tau=p i / ( 2 ∗w)
   t 0 =1.0 e −15
   t 2=tau ∗5
   a i =0
   aint=0
   a l e v 1 =1/akk
   do 2 t=t0 , t2 , dt
   p t t=pa ∗ s i n (w∗ t )
   pok=(−1∗ a l ) / ( p t t ∗ p t t )
   pr=expo ∗∗ pok
   aint=aint+pr ∗ dt
   r=aint−a l e v 1
   k=k+1
    i f ( r ) 7 ,7 ,8
7 continue
2 continue
8 continue
   p1=pb−p t t
   TEM=t t −273.15
   t 1=t ∗ 1 . 0 e6
   p11=p1 / 1 . 0 e6
   a r o =(2∗ s i g ) / p t t
   a r o 1=a r o /(1. − r o v / r o l )
                                      Kravchenko N. Y., Kulyabov D. S.                                      79




                                        Figure 1. Block diagram



   a r o 2=a r o 1 ∗ 1 . 0 e9
   write ( ∗ , 1 0 ) tem , t1 , p11 , a r o 2
10 format ( ’ ␣ | ␣ ␣ ␣ ’ , f 6 . 1 , ’ ␣ ␣ | ␣ ␣ ␣ ␣ ’ , f 7 . 4 , ’ ␣ ␣ ␣ ␣ ␣ | ␣ ’ , f 8 . 5 , ’ ␣ | ␣
    ˓→ ’ , f 7 . 3 , ’ ␣ ␣ ␣ | ’ )
   goto 1
   end


         6.    The program for the numerical solution of the equation (1)
   We have created a program for the numerical solution of the cavitation equation in
the Fortran programming language. It work is based on the Runge-Kutta method. The
block diagram of the program is shown in the figure 1.
   Initially, the main program asks for the values of external parameters, such as fluid
temperature, oscillation frequency, and others. Then the main program refers to an
array of tabular data for the values of surface tension, fluid viscosity, fluid pressure,
vapor pressure at a given temperature. These tabular data are discrete values and do
not always correspond to a given temperature. Therefore, the main program refers to
auxiliary subroutine 1, which approximates or extrapolates the table data to a given
point.
   To calculate parameters such as the initial radius of the cavity, the pressure at which
the first cavitation nucleus appears, the initial phase of external oscillations, the main
program refers to subroutine 2, which calculates these values based on the data already
calculated by subroutine 1.
   Subroutine 3 then receives from subprogram 2 a task to calculate the time 𝑡1 during
which the first cavitation nucleus appears in the fluid. The required tabular data is
80                                                                                            ITTMM—2019


requested from subroutine 1. The result of the calculation is reported to the main
program.
   Having collected all the necessary data, the main program calculates the basic
cavitation equation for the maximum amplitude of oscillations of the cavity.
   Below is a part of the main program (see Listing 2) for the numerical solution of this
system of equations, written in the programming language Fortran:

        Listing 2: Program for the numerical solution of the equation (1)
C          =====program c a v i t a t i o n=========
         external                   equ , out
         dimension pt ( 5 ) , u ( 2 ) , du ( 2 ) , au ( 8 , 2 )
         common / a / a , b , c , d , e , g
         common /b/ dt , j , i p d o s
         open ( unit =1 , f i l e= ’ im . dat ’ , status= ’ o l d ’ )
         open ( unit =2 , f i l e= ’ im . out ’ )
 1       format ( 8 x , e11 . 3 )
 2       format ( 8 x , f 1 0 . 3 )
 3       format ( 8 x , i 8 )
         read ( 1 , 1 ) r n o l , pnol , sigma , pmax , tau
         read ( 1 , 2 ) gamma , rho , v n o l
         read ( 1 , 3 ) i c h a s t , i p d o s
         write ( ∗ , ∗ ) r n o l , pnol , sigma , pmax , tau
         write ( ∗ , ∗ ) gamma , rho , v n o l
         write ( ∗ , ∗ ) i c h a s t , i p d o s
         read ∗
C          ==========n o r m a l i z a t i o n============
          p i =3.14159
         t e n s o =2∗sigma / r n o l
         denso=rho ∗ r n o l ∗ r n o l
         omega=1/tau
         pa=pmax∗exp ( 1 . 0 )
         deno=denso ∗omega∗omega
         a=( p n o l+t e n s o ) / deno
         b=t e n s o / deno
         c=p n o l / deno
         d=pa / p n o l
         g=3∗gamma+1
         dt =1./ i c h a s t
C          ==========p e r i o d s t e p===========
         t =0.
         write ( ∗ , ∗ ) ’ n o r m a l i z a t i o n : ’ , a , b , c , d , g , tau , dt , t
          i =1
          j =1
C          ========p a r a m e t e r s RKGS=========
         pt ( 1 ) =0.
         pt ( 2 )=i p d o s
         pt ( 3 )=dt
         pt ( 4 ) =1.0 e−4
         pt ( 5 ) =0.
         u ( 1 ) =1.
         u ( 2 )=v n o l
                             Kravchenko N. Y., Kulyabov D. S.                          81


         du ( 1 ) =0.5
         du ( 2 ) =0.5
         write ( 2 , 4 )
 4       format ( ’ ␣ t / tau ␣ ␣p ( t ) ␣ ␣R/Ro␣ ␣dR/ dt ␣ ␣ j ’ )
          j =1
          c a l l r k g s ( pt , u , du , 2 , imsg , equ , out , au )
         write ( 2 , ∗ ) imsg
         write ( ∗ , ∗ ) imsg
         stop
         end
C          =========subroutine equ=========
         subroutine equ ( t , u , du )
         dimension u ( 2 ) , du ( 2 )
         common / a / a , b , c , e , g
         common / c / pe
         pe=( t ∗ ∗ 2 ) ∗ ( exp(−1∗ t ) )
         p=d∗ pe
         au=a / ( u ( 1 ) ∗∗ g )
         bu=−1∗b / ( u ( 1 ) ∗ ∗ 2 )
         cu=−1∗c ∗(1−p ) /u ( 1 )
         uu =1.5∗ u ( 2 ) ∗u ( 2 ) /u ( 1 )
         du ( 2 )=au+bu+cu+uu
         du ( 1 )=u ( 2 )
         return
         end
C          ========subroutine out==========
         subroutine out ( t , u , du , imsg , numd , pt )
         dimension u ( 2 ) , du ( 2 ) , pt ( 5 )
         common /b/ dt , j , i p d o s
         common / c / pe
          i f ( t−dt ∗ j ) 1 , 2 , 2
 2       continue
         pimp=50∗pe /exp ( 1 . 0 )
         write ( 2 , ∗ ) t , pimp , u ( 1 ) , u ( 2 ) , j
         write ( ∗ , ∗ ) t , pimp , u ( 1 ) , u ( 2 ) , j
          j=j +1
 1       continue
          i f ( j −i p d o s ) 4 , 4 , 5
 5       continue
         write ( ∗ , ∗ ) j , i p d o s
         pt ( 5 ) =1.
 4       continue
         return
         end


                                   7.   Conclusions
   Thus, in this paper we consider the processes taking place in the liquid phase, such
as nucleation in liquids, nucleation in liquid metals, electrical explosion of conductors
and spark cavitation.
82                                                                                  ITTMM—2019



                                                                                            Table 1
                                Stretching time 𝑡1 , mks


            Temperature, 𝑡0 𝐶      𝜈 = 100kHz          𝜈 = 250kHz     𝜈 = 600kHz
                    250               0.84                0.47            0.133
                    300               0.81                0.46            0.129
                    350               0.76                0.45            0.120
                    373               0.54                0.22            0.092


                                                                       Table 2
The maximum amplitude of 𝑅/𝑅0 and the oscillation period of 𝑇1 /𝑇 of a bubble
                         at different frequencies


           𝜈, MHz     500    100     50        10           5          0.5         0.25
                       1      10    120
         (︀ 𝑅 )︀
          𝑅0 𝑚𝑎𝑥
                                             8 · 103     3 · 104    7.3 · 105     2 · 106
            𝑇1
            𝑇
                     0.25    0.5    0.6       2.5          5.0        12.5         15.0

    It is established that all the mentioned processes are well described by the basic
equation of cavitation.
    The indicated equation is solved numerically by the Runge-Kutta method. For this
purpose, a program in the Fortran programming language has been created, a scheme of
its work has been presented, and a method has been described for determining the time
of appearance of cavitation nuclei using the numerical integration method.
    The stretching time 𝑡1 for different frequencies of external influence 𝜈 is presented
in Table 1, the maximum amplitude and period of natural oscillations of a bubble at
different frequencies are given in Table 2.

                                   Acknowledgments
   The publication has been prepared with the support of the “RUDN University
Program 5-100”.

                                      References
1.   Semenchenko V.K. Selected Chapters of Theoretical Physics. - M .: Enlightenment,
     1966. -396 p.
2.   Martynyuk M.M., Kravchenko N.Yu. Limit of thermodynamic stability of a liquid
     phase in the field of nefative pressure. Journal of Physical Chemistry. 1998. V. 72.
     N 6. pp. 998-1001.
3.   Tamanga P.A., Martynyuk M.M., Kravchenko N. Yu. Spinodal of Liquid Phase on
     Basis of Generalized Berthelo’s Equation. Bulletin of Peoples’ Friendship University
     of Russia. Series: Mathematics, Informatics, Physics. 2001. N 9. pp. 56-58.
4.   Kravchenko N. Yu., Martynyuk M.M. Dynamics of Homogeneous Cavitation Bub-
     bles in Water under Large Amplitude Pressure Oscillations. Bulletin of Peoples’
     Friendship University of Russia. Series: Mathematics, Informatics, Physics. 2000. N
     8. pp. 118-121.
5.   Skripov P.V., Pavlov P.A. The effect of gas saturation on the achievable overheating
     of water. TVT, 1985. V.23. No 4. p.826-827.
                             Kravchenko N. Y., Kulyabov D. S.                          83


6.  Skripov P.V. Metastable liquid. - M.: Science, 1972. - 312 p.
7.  Teplofizicheskiye svoystva zhidkostey v metastabil’nom sostoyanii V.P. Skripov,
    Ye.N. Sinitsyn, P.A. Pavlov i dr. M.:Atomizdat, 1980. p.7-94.
8. Martynyuk M.M. Fazovyye perekhody pri impul’snom nagreve. – M.: Izd. RUDN,
    1999.
9. Dozier M.C. Bulletin of American Physical Society. Ser.2. 1976. V.21. No. 9. P.1040.
10. Vitkovitsky I.M. Physics of Fluids. 1964. V.7. No. 4. P.612.
11. Burkhalter P. Davis J., Rauch J. et al. Applied Physics. 1979. V. 50. P. 705.
12. Martynyuk M.M., Tamanga P.A., Kravchenko N.Yu. The Titanium Phase Dia-
    gram at the Phase Transition Region Liquid-Vapor. Bulletin of Peoples’ Friendship
    University of Russia. Series: Mathematics, Informatics, Physics. 2002. N 10. pp.
    121-125.
13. Martynyuk M.M J. tech. physics. 1978. T.48. No 7. P.1482.
14. Martynyuk M.M Radio engineering and electronics. 1980. No 1. P.157.
15. Golubnichy P.I. Experimental study of cavitation phenomena and related effects
    with a powerful pulsed energy release in a condensed medium. (Thesis ... doctor.phiz.-
    mat.nauk). Voroshilovgrad, 1986.
16. Golubnichy P.I., Gromenko V.M., Filonenko A.D. Letters in ZhTF. 1979. V. 5. AT
    12. P.1385–1388.
17. Nikolay Yu. Kravchenko The Numerical Solution of the Rayleigh-Plisset Equation
    for Spark Cavitation and Calculation of the Maximum Temperature and Pressure
    in a Cavity. Journal of Mechanics of Continua and Mathematical Sciences, Special
    Issue-1, March (2019), pp. 465-473. doi: 10.26782/jmcms.2019.03.00046.