Research on Face Fluid Field and Seal Performance of T-shape Groove Dry Gas Seal
To obtain more details about the fluid field and high stability of dry gas seal, according to Reynolds equation of compressible perfect gas, on isothermal condition, the controlling equation of gas between the T-shape groove dry gas seal faces is established, and the controlling equation is converted into a non-dimensional equation. The gas flow capacity of T-shape groove dry gas seal is reached with computer simulation in Fluent software, on the basis of numerical simulation, the working parameters (such as, rotating speed, pressure, viscosity of medium, etc.) and the geometric parameters (such as, groove number, groove deep, groove width ratio, balance clearance, etc.) which affect seal performance, are discussed in detail, and the affecting curves are gained. The parameters ( such as, groove deep, balance clearance) which affect seal performance mostly should be chosen correctly in design. The general principle for selecting geometric parameters and working parameters of T-shape groove dry gas seal are obtained, for example, the groove number should be chosen within 12¿16, the groove deep should be chosen within 4¿6 μm, the balance clearance should be chosen within 0.8¿1.4 μm. It offers theoretical support for engineering design and application of T-shape groove dry gas seal.
Finite Element Analysis of the Spiral Groove Gas Face Seal at the Slow Speed and the Low Pressure Conditions — Slip Flow Consideration
A Finite Element model for the noncontacting gas face seal is developed based on the modified Reynolds Equation developed by Fukui and Kaneko (4), (5) that considers the slip flow effects. Numerical studies of a representative spiral groove seal at the slow speed (≤, 500 rpm) and the low pressure (≤ .303 MPa) conditions showed that slip flow can significantly affect the seal performances such as the lift-off speed, leakage rate, load carrying capacities. Without the consideration of the slip flow effect, the lift-off speed and the corresponding leakage rate would be greatly underestimated, especially at near ambient pressure condition. By examining the F-h characteristic curves, it was found that under the parameters presented in the present study the slip flow could be significant for Knudsen number, Kn as small as .05, and the slip flow in effect reduces the viscous pumping resulting in a loss of load carrying capacities. Presented at the 55th Annual Meeting Nashville, Tennessee May 7–11, 2000
CNC Desktop Vertical Machining Bench Design and Cooling Fluid Application
Today's manufacturing technologies, the human work force is used and at least a minimum level of margin of error is used in CNC machines. Desktop CNC machine tools and CNC machine tools are developed in parallel with the development of personal computers. This study provides CNC training institutions for education, small and medium-sized enterprises for commercial purposes use the low-cost desktop machine has been designing and manufacturing of CNC vertical machining was carried out. Desktop CNC machine tools and production capacity to handle the kind of material was applied to increase the cooling fluid. Through A199 and Fe37 the cooling fluid application desktop CNC machine tools, such as processing of materials that are difficult to successfully processed. Keywords—CNC, Desktop CNC Machine, CNC Design