Analysis of a Singular Boussinesq Model

TL;DR

This paper investigates a singular Boussinesq model with a sign-changing Biot-Savart kernel, demonstrating finite time blow-up under specific parameters, advancing understanding of singularity formation in fluid dynamics models.

Contribution

It extends previous simplified models by incorporating the sign-changing kernel, showing that finite time blow-up still occurs, thus addressing a more realistic and complex scenario.

Findings

Finite time blow-up persists with sign-changing kernel

Analysis reveals the balance of competing terms affects regularity

Results support the singularity formation scenario in fluid models

Abstract

Recently, a new singularity formation scenario for the 3D axi-symmetric Euler equation and the 2D inviscid Boussinesq system has been proposed by Hu and Luo based on extensive numerical simulations [15, 16]. As the firrst step to understand the scenario, models with simplified sign-definite Biot-Savart law and forcing have recently been studied in [7, 6, 8, 12, 14, 18]. In this paper, we aim to bring back one of the complications encountered in the original equation - the sign changing kernel in the Biot-Savart law. This makes analysis harder, as there are two competing terms in the fluid velocity integral whose balance determines the regularity properties of the solution. The equation we study here is based on the CKY model introduced in [6]. We prove that finite time blow up persists in a certain range of parameters.