...Lei Wang; Bengt Sundén; Andreas Borg; Hans Abrahamsson The heat transfer characteristics of an impinging jet into a crossflow have been investigated by the liquid crystal thermography technique. The jet nozzle is circular and is inclined at 10 deg with respect to the target wall. In a turbulent...

...Bahman Abbasi; Jungho Kim Spray cooling heat transfer measurements of PF-5060 on smooth flat surfaces were obtained using a microheater array operated at constant temperatures using two nozzles (hollow cone and full cone), three nozzle-to-heater standoff distances (3, 5, and 7 mm), four nozzle...

..., gas turbines, microcombustors, and microthrusters. In this study, we derive a closed-form approximation for the inverted and more commonly used solution relating performance directly to the nozzle area ratio. The inverted expression provides a computationally efficient alternative to solutions based...

...A. Hajari; S. H. Seyedein; M. R. Aboutalebi In this work a three-dimensional fluid flow and heat transfer model was developed to predict the flow pattern and superheat dissipation in funnel shaped mold of a thin slab continuous caster with a novel tetrafurcated design for the submerged entry nozzle...

.... In this study, hollow cone, full cone, and flat fan sprays, operated at three standoff distances, five spray pressures, and two nozzle orientations, were used to identify the relation between the impingement pressure and the heat transfer coefficient in the single-phase regime. PF-5060, PAO-2, and PSF-3 were...

... for a rectangular beam with side powder injection. In this article, a custom-designed flat nozzle delivers the powder material into a distinct molten pool formed by a HPDL with a rectangular beam. A powder model is first presented to reveal the powder flow behavior below the flat nozzle. Key parameters...

...Volkan Kırmacı; Onuralp Uluer; Kevser Dincer An experimental investigation has been carried out to determine the thermal behavior of cooling fluid as it passes through a vortex tube and the effects of the orifice nozzle number and the inlet pressure on the heating and cooling performance...

...Y. Q. Zu; Y. Y. Yan; J. Maltson In this paper, the heat transfer characteristics of a circular air jet vertically impinging on a flat plate near to the nozzle ( H / d = 1 – 6 , where H is the nozzle-to-target spacing and d is the diameter of the jet) are numerically analyzed. The relative...

... = 200 and 500, the Prandtl number Pr = 0.71 , the dimensionless space between the nozzle and impingement surface H = 1.0 , and the Strouhal number Sf = 0 – 1.0 . Oscillation induced both the enhancement and depression of the local heat transfer. The local heat transfer was improved at a comparatively...

...Volkan Kırmacı; Onuralp Uluer This paper discusses the experimental investigation of vortex tube performance as it relates to cold mass fraction, inlet pressure, and nozzle number. The orifices have been made of the polyamide plastic material. Five different orifices, each with two, three, four...

...Xianchang Li; Ting Wang Effective cooling of gas turbine combustor liners, combustor transition pieces, turbine vanes (nozzles), and blades (buckets) is a critical task to protect these components from the flue gas at extremely high temperature. Air film cooling has been successfully used to cool...

..., aluminum, copper, silver, Constantan, and silicon; covering a range of Reynolds number (220–900), Ekman number ( 7.08 × 10 − 5 – ∞ ) , nozzle-to-target spacing ( β = 0.25 – 1.0 ) , disk thicknesses to nozzle diameter ratio ( b ∕ d n = 0.25 – 1.67 ) , and Prandtl number (1.29–124.44) using ammonia ( N H 3...

... sprayed with a full cone nozzle using PF-5060 at 30 ° C and nozzle pressure differences from 1.36 – 4.08 atm ( 69 – 121 ml ∕ min ) . In all cases, the enhanced surfaces improved thermal performance compared to the flat surface. Longer fins were found to outperform shorter ones in the single-phase regime...

...Xi Jiang; Hua Zhao; Kai H. Luo A non-premixed impinging jet flame at a Reynolds number 2000 and a nozzle-to-plate distance of two jet diameters was investigated using direct numerical simulation (DNS). Fully three-dimensional simulations were performed employing high-order numerical methods...

... the performance of the present model: (i) fully developed channel flow with Re τ =395, (ii) backward-facing step with an expansion ratio of 1.2 and Re=5200 base on the step height, and (iii) circular impingement with the nozzle-to-wall distance H=4D and Re=20,000. It is believed that the new model has good...

... has been applied. A column of liquid is placed between a nozzle outlet and a moving wall, and calculations are done in two dimensions with a fixed distance between the nozzle and the wall. The results show that the wall velocity creates a circulation near the meniscus base, resulting in transient heat...

... angle), blowing ratio, and upstream nozzle wakes around the leading edge region. Results show that rotation has a significant impact on the leading edge film cooling distributions with the average film cooling effectiveness in the leading edge region decreasing with an increase in the rotational speed...

...Anna Pavlova; Michael Amitay The efficiency and mechanisms of cooling a constant heat flux surface by impinging synthetic jets were investigated experimentally and compared to cooling with continuous jets. Effects of jet formation frequency and Reynolds number at different nozzle-to-surface...

...Valery P. Lebedev; Vadim V. Lemanov; Victor I. Terekhov In the present work we experimentally examined the effect of enhanced freestream turbulence on the film-cooling efficiency in an axisymmetric supersonic nozzle. A considerable reduction in the film-cooling efficiency was observed...

...Yumin Xiao; R. S. Amano; Timin Cai; Jiang Li Use of aluminized composite solid propellants and submerged nozzles are common in solid rocket motors (SRM). Due to the generation of slag, which injects into a combusted gas flow, a two-phase flow pattern is one of the main flow characteristics...