RETRACTED: Acoustic mechanism of the vertical incidence and diffusion domain of the front protective wall containing microfibers-HT400P

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the author. After publication, the author contacted the journal regarding errors affecting section 4.3.2 of the article (Influence of air damping coefficient of double wall cavity). The data is lacking experimental verification due to data loss and errors. After careful consideration, the author has requested retraction and the Editor-in-Chief has agreed. The authors offer their apologies to readers, Editors and reviewers of this paper.