Dissipation of nonlinear acoustic waves in thermoviscous pores

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Sahithi, Krishna, Gupta, Prateek
Format: Preprint
Veröffentlicht: 2024
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866909108682096640
author Sahithi, Krishna
Gupta, Prateek
author_facet Sahithi, Krishna
Gupta, Prateek
contents We derive a nonlinear acoustic wave propagation model for analysing the thermoviscous dissipation in narrow pores with wavy walls. As the nonlinear waves propagate in the thermoviscous pores, the wave-steepening effect competes with the bulk dissipation, as well as the thermoviscous heat transfer and shear from the pore walls. Consequently, the length scale of the wave is modified. We use the characteristic nonlinear wave thickness scale to obtain linear and nonlinear wave equations governing the unsteady shock-wall interaction. We also perform two-dimensional shock-resolved DNS of the wave propagation inside the pores and compare the results with model equations. We show that for flat-walls and shock strength parameter $ε$, the dimensional wall heat-flux and shear scale as $ε$. For wavy walls, the scaling becomes $ε^{3/2 - n(k)}$ where $k$ is the wall-waviness wavenumber and the exponent $n$ increases from $0.5$ for $k=0$ to $n(k)\approx0.65$ for $k=10$, $n(k)\approx 0.75$ for $k=20$, and $n(k)\approx0.85$ for $k=40$. Hence, increasing the wall waviness reduces the dependence of the wall heat-flux and shear on nonlinear acoustic wave strength.
format Preprint
id arxiv_https___arxiv_org_abs_2402_09889
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Dissipation of nonlinear acoustic waves in thermoviscous pores
Sahithi, Krishna
Gupta, Prateek
Fluid Dynamics
We derive a nonlinear acoustic wave propagation model for analysing the thermoviscous dissipation in narrow pores with wavy walls. As the nonlinear waves propagate in the thermoviscous pores, the wave-steepening effect competes with the bulk dissipation, as well as the thermoviscous heat transfer and shear from the pore walls. Consequently, the length scale of the wave is modified. We use the characteristic nonlinear wave thickness scale to obtain linear and nonlinear wave equations governing the unsteady shock-wall interaction. We also perform two-dimensional shock-resolved DNS of the wave propagation inside the pores and compare the results with model equations. We show that for flat-walls and shock strength parameter $ε$, the dimensional wall heat-flux and shear scale as $ε$. For wavy walls, the scaling becomes $ε^{3/2 - n(k)}$ where $k$ is the wall-waviness wavenumber and the exponent $n$ increases from $0.5$ for $k=0$ to $n(k)\approx0.65$ for $k=10$, $n(k)\approx 0.75$ for $k=20$, and $n(k)\approx0.85$ for $k=40$. Hence, increasing the wall waviness reduces the dependence of the wall heat-flux and shear on nonlinear acoustic wave strength.
title Dissipation of nonlinear acoustic waves in thermoviscous pores
topic Fluid Dynamics
url https://arxiv.org/abs/2402.09889