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تسجيل مستخدم جديدDynamics of the Density of Quantized Vortex-Lines in Superfluid Turbulence
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The quantization of vortex lines in superfluids requires the introduction of their density $C L(B r,t)$ in the description of quantum turbulence. The space homogeneous balance equation for $C L(t)$, proposed by Vinen on the basis of dimensional and physical considerations, allows a number of competing forms for the production term $C P$. Attempts to choose the correct one on the basis of time-dependent homogeneous experiments ended inconclusively. To overcome this difficulty we announce here an approach that employs an inhomogeneous channel flow which is excellently suitable to distinguish the implications of the various possible forms of the desired equation. We demonstrate that the originally selected form which was extensively used in the literature is in strong contradiction with our data. We therefore present a new inhomogeneous equation for $C L(B r,t)$ that is in agreement with our data and propose that it should be considered for further studies of superfluid turbulence.
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This is a Reply to Nemirovskii Comment [Phys. Rev. B 94, 146501 (2016)] on the Khomenko et al, [Phys.Rev. B v.91, 180504(2016)], in which a new form of the production term in Vinens equation for the evolution of the vortex-line density $cal L$ in the
thermal counterflow of superfluid $^4$He in a channel was suggested. To further substantiate the suggested form which was questioned in the Comment, we present a physical explanation for the improvement of the closure suggested in Khomenko et al [Phys.Rev. B v. 91, 180504(2016)] in comparison to the form proposed by Vinen. We also discuss the closure for the flux term, which agrees well with the numerical results without any fitting parameters.
Describing superfluid turbulence at intermediate scales between the inter-vortex distance and the macroscale requires an acceptable equation of motion for the density of quantized vortex lines $cal{L}$. The closure of such an equation for superfluid
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