Technology

  2010 MAR 9 - (VerticalNews.com) -- According to recent research from Roorkee, India, "An experimental investigation has been carried out to determine the heat transfer coefficient during pool boiling of water over a bundle of vertical stainless steel heated tubes of 19.0 mm diameter and 850 mm height."

  "The p/D of bundle was 1.66 and was placed inside a glass tube of 100 mm diameter and 900 mm length," wrote A. Gupta and colleagues ...read more

  2010 MAR 9 - (VerticalNews.com) -- "This paper presents the effects of cooling of a hot tube on the temperature separation (the temperature reduction of cold air) and cooling efficiency in a counter-flow Ranque-Hilsch vortex tube (RHVT). In the experiments, the hot tube is directly cooled by cooling water jacket," investigators in Bangkok, Thailand report.

  "The obtained results reveal that cooling water plays an important role in promoting the energy separation in the RHVT. Consequently, the temperature reduction of the cold tube (T-i - T-c) and thus cooling efficiency in the RHVT with cooling of a hot tube is found to be higher than those of the RHVT without the cooling, under the similar operating conditions," wrote S. Eiamsaard and colleagues ...read more

  2010 MAR 9 - (VerticalNews.com) -- According to recent research from Nibong Tebal, Malaysia, "Three-dimensional simulation and experimental investigation of polymer rheology in a miniature injection molding process is presented. The material used in the study is ABS plastic, Toyolac 250-X10 and tests are carried out at different temperatures of the molten thermoplastic which is injected into the mold cavity."

  "FLUENT 6.3 software is used in the simulation to verify the viscosity model (Cross model) and the Volume of Fluid (VOF) method is applied for the melt front tracking. The model is validated by means of experiments performed by using Davenport High Shear Viscometer with injection nozzle. It has been observed that there exists an optimum combination of temperature viscosity and shear rate for the selected injection molding process. Accordingly, the temperature range 200-260 degrees C and shear rate 10(2)-10(4) s(-1) are found good for the process. The mold flow profiles for various temperatures and time steps are also presented," wrote C.Y. Khor and colleagues ...read more