On thermal transpiration and thermomolecular pressure difference

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Wang, Kai-Li, Chen, I-Kun
Natura: Preprint
Pubblicazione: 2026
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866911530743758848
author Wang, Kai-Li
Chen, I-Kun
author_facet Wang, Kai-Li
Chen, I-Kun
contents In this article, we demonstrate the phenomenon of thermal transpiration in a bounded convex domain. We employ the stationary Boltzmann equation with a cutoff potential. For boundary condition, we partition the boundary into diffuse reflection and incoming regions. We establish the existence of solution in a weighted $L^\infty$ space. Furthermore, we consider a convex domain with diffuse reflection boundary condition in the middle and incoming boundary condition at the two ends. We first consider Maxwellians with the same pressure but different temperatures at the two ends. We prove that the total flux $U(x)$ is directed toward the hot end. Furthermore, we derive an estimate for the total flux: \begin{align} U(x)\geq C\left(1-\frac{1}{\sqrt{T_2}}\right). \end{align} In addition, we show that when the pressures and temperatures on the two ends satisfy the relation \begin{align} \frac{P_1}{P_2}=\sqrt{\frac{T_1}{T_2}}, \end{align} the total flux of the solution is of order $\mathcal{O}(\frac{1}κ)$. This result is consistent with Knudsen's finding of thermomolecular pressure difference in 1909.
format Preprint
id arxiv_https___arxiv_org_abs_2602_21079
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle On thermal transpiration and thermomolecular pressure difference
Wang, Kai-Li
Chen, I-Kun
Analysis of PDEs
35Q20, 76P05, 82C40, 35B40
In this article, we demonstrate the phenomenon of thermal transpiration in a bounded convex domain. We employ the stationary Boltzmann equation with a cutoff potential. For boundary condition, we partition the boundary into diffuse reflection and incoming regions. We establish the existence of solution in a weighted $L^\infty$ space. Furthermore, we consider a convex domain with diffuse reflection boundary condition in the middle and incoming boundary condition at the two ends. We first consider Maxwellians with the same pressure but different temperatures at the two ends. We prove that the total flux $U(x)$ is directed toward the hot end. Furthermore, we derive an estimate for the total flux: \begin{align} U(x)\geq C\left(1-\frac{1}{\sqrt{T_2}}\right). \end{align} In addition, we show that when the pressures and temperatures on the two ends satisfy the relation \begin{align} \frac{P_1}{P_2}=\sqrt{\frac{T_1}{T_2}}, \end{align} the total flux of the solution is of order $\mathcal{O}(\frac{1}κ)$. This result is consistent with Knudsen's finding of thermomolecular pressure difference in 1909.
title On thermal transpiration and thermomolecular pressure difference
topic Analysis of PDEs
35Q20, 76P05, 82C40, 35B40
url https://arxiv.org/abs/2602.21079