Numerical Simulation of Airflow Field in Grinding
With a view to find better ways for coolant delivery, the boundary layer of peripheral air of grinding wheel is simulated using finite volume method. By means of introducing Sparlart-Allmaras (SA) model into the mathematical model, the airflow field is calculated and pressure distributions and velocity distributions are obtained by simulations. An experiment is run to testify solutions of numerical simulation accordingly. The simulation solutions are in consistent with the experiment results on the whole. Therefore, this simulation method holds true for predicting the performances of airflow field around grinding wheel when grinding wheel rotates at high speeds. Based on the numerical solution results obtained in this paper, the causes to disadvantage of coolant delivery into the grinding zone are studied from the point of view of the pressure and velocity. In the end, one optimizing way of coolant delivery is specified and a few useful conclusions are drawn for applications of coolant delivery in the course of high speed grinding. Methods and conclusions of this research are available for perfection of grinding theory and applications of cooling in the future.
Simulation of Grinding Temperature Field Based on the Application of MATLAB and VB
This paper introduced the research of simulation in grinding temperature field based on the hybrid programming between MATLAB and VB.The simulation integrates their advantages,which were powerful mathematic calculation capacity and graphic capacity of MATLAB,and VB's friendly visual interface.When inputting programmed command of temperature pattern or grinding parameters directly,the temperature distribution could be gained through calculating by MATLAB,and besides,it could also be applied to other physical quantity simulation,for example grinding force,surface roughness and so on.
Comparison between Two Chemicals for Reducing Scale Formation in Reverse Osmosis Systems
In this present research was transacted with the calcium carbonate scale inhibition on the membrane surface of the reverse osmosis desalination system. Influence of changing feed solution flow rate (10-25)l/h, pH of the feed solution (6-10) on the recovery ,penetrate flow rate and total dissolved solid in (RO) system by using solution of calcium carbonate as feed solution was investigated, furthermore the effect of adding two types of scale inhibitor ,zinc chloride and polyamino polyether methylene phosphonate with difference concentration (2-8)mg/l for zinc chloride and (8-15) mg/l for polyamino polyether methylene phosphonate was calculated. The results showed that the permeate rate increases as the feed flow rate augmentation ,while it reducing with time, the total dissolved solids decreases as the feed flow rate increases while it increases with time and recovery rate decreases as the feed flow rate increases and it also decreases with time. It was concluded that the permeate rate decreases as the feed solution pH value increases and it cause high scale forming thus decrease the permeate TDS.By adding the scale inhibitor, it was found that the permeate rate and recovery rates increases as the concentration of inhibitor increases while the total dissolved solids decreases in the permeate with increasing the concentration of both inhibitors .It was discovered that Polyamino polyether methylene phosphonate more sturdy than zinc chloride as scale inhibitor for reverse osmosis desalination system in all concentrations was studied in this article.