Study of the conditions for boiling onset of cryogenic fluids

A study on the vapour nucleate stability in a taper recess resulted in obtaining the data, permitting to determine the size of the recess characterizing the boiling onset, from the known wetting angle and surface finish quality. An analysis of the curves presented permits a conclusion to be made that improvement in the surface finish quality results in decreasing a non-dimensional radius of active recess, Tsub(c)=rsub(c)bsup(1/2) (rsub(c)=dimensional value of the radius, b=Δrhog/σ, g=gravitational acceleration, σ - surface tension, Δrho=rho'-rho'', rho', rho'' - densities of liquid and gas). Decrease of the moistening angle and increase of overload eta have a similar effect. The dependence r=βtausup(n) (r=bubble radius; tau=time; β=coefficient) has been analyzed for quasistatic mode of bubble growth