Jet Momentum Ratio Research Articles

Criterion for Establishing Similar Air Flow Patterns (Isothermal) in Slotted-inlet Ventilated Enclosures

As measures of air flow pattern similarity in Slotted-Inlet Ventilated Enclosures (SIVE), the inlet Reynolds number (Re) and the inlet jet momentum number (J) were found to be inappropriate. A criterion was derived from the ratio of inlet jet momentum to the momentum loss due to shear along the inside walls and was denoted as inlet jet momentum ratio (RM). Appropriateness of the criterion was shown analytically and was confirmed experimentally. Further investigations of the momentum ratio and near-floor air velocity relationship, and its relation to animal comfort, is recommended.

The effect of thyroid therapy on children: Anne Topper and Philip Cohen. Am. Jour. Dis. Child., February, 1928, xxxv, 2

Spray formation is important for liquid fuel combustion from the perspective of emissions and sustaining combustion. Employing swirl flow increases turbulent intensity, which leads to a much-desired outcome for sprays in a reduction of the jet breakup length, better air-fuel mixing and vaporization characteristics, and stabilizes the combustion operation. The present investigation endeavors to characterize the near field spray developing region of a swirl airblast atomizer. The high-speed digital imaging system is employed to record the unsteady dynamics when the liquid jet breaks to form mono-disperse or poly-disperse drop size distribution depending upon the atomizing air to liquid jet momentum ratio. The coherent spatial nature of the atomization process is identified using Proper Orthogonal Decomposition (POD) of acquired high-speed images of the spray in the near field. The simultaneous droplet size and velocities (axial, radial, and tangential) are measured through Phase Doppler Particle Analyzer (PDPA) technique to quantify the effect of the flow field on spray characteristics in the near field of an atomizer. Joint probability distributions of drop size and velocity along with Weber number distribution provide insight into the spray developing near field region. The spatial variations in the drop size distribution are found to be a function of turbulent Weber number (Wet) and shear Weber number (Wes) distribution. Double Gaussian function representing superimposed distributions for larger and smaller droplets provides the highest confidence fit for both velocity and dropsize distributions throughout the flow field. The volume-averaged statistics are proposed for a better description of the actual spray quality.