Existence of an exact solution of the Navier-Stokes equations representing swirling flow consisting of two fluid layers is proven. It is assumed that the fluid in the bottom layer is injected into the swirl from a rotating disk. This describes the case when a disk melts in an ambient fluid and the melted fluid is removed by rotation of the disk.

Combustion instability is a process which involves unsteady chemical kinetic, fluid mechanic, and acoustic processes. It can lead to unstable behavior and be detrimental in ways ranging from faster part fatigue to catastrophic system failure. In terms of combustion methodology, combustion instability has been a key issue for lean premixed combustion. The primary objective of this work is to imp...

New exact solutions, obtained for centrifugal convection of a compressible fluid in pipes and annular pipes, explain axially elongated counterflow and energy separation—poorly understood phenomena occurring in vortex devices, e.g., hydrocyclones and Ranque tubes. Centrifugal acceleration ~which can be up to 10 times gravity in practical vortex tubes!, combined with an axial gradient of temperat...

Respiratory tract infections (RTI) frequently cause hospital admissions among adults. Diagnostic viral reverse transcriptase PCR (RT-PCR) of nose and throat swabs (NTS) is useful for patient care by informing antiviral use and appropriate isolation. However, automated RT-PCR systems are not amenable to utilizing sputum due to its viscosity. We evaluated a simple method of processing sputum samp...