Numerical Simulation And Optimum Design Of Spirally Grooved Runner Roller

Spiral groove roller was widely used for its large heat transfer area between the runnerand the roller.But the design and processing of spiral runner are more complex than straightrunner and the structure and layout of the runner have significant impact on the surfacetemperature field of the roller, therefore, it’s important to optimize the design of spiral runner.In this paper, the spiral groove roller model was firstly simplified reasonably, and thecomputational mesh model of the runner roller was obtained by using ICEM, a kind ofsimulative pretreatment software. The temperature field of runner roller can be obtained byFluent, a kind of flow field simulative software and the simulation results can be analyzed byCFD-Post, a kind of post processing software. Then main results can be obtained such as therate of fluid in runner roller, the fluid temperature field, the roller temperature field and theheat exchange density of the surface of runner.The reasons for the heterogeneous temperature of the outside surface of the roller areobtained by the analysis of simulation results. On this basis, in order to improve theuniformity of temperature distribution of the outside surface of the roller, the structure ofrunner and the mode of operation were optimized repeatedly. The conclusions are as follows:1. The simulation results show that the temperature of fluid at the end of original runneris lower, and there is a longer period of low temperature region on the outside surface of thecorresponding roller, which seriously affects the uniformity of temperature of the outsidesurface of the roller. As the exit set at the end of the runner, the flow rate of flow field is moreuniform and the temperature difference of flow field was greatly reduced, but the structure ofthe roller is more complex. When the fluid in the end of runner was deleted, the temperaturefield of roller was further improved; and the structure of the roller is not so complex.2. The direction where runner roller rotates has great effects on the temperatureuniformity of outside surface of the roller. When the temperature of fluid flowing is in thesame direction with the roller is low, the heat exchanging efficiency between the fluid and theroller is weak; Whereas the result will be contrary. In addition, the length of the roller, the rateof the flow and the heat transfer coefficient of the outside surface also has an obviousinfluence on the temperature of the roller.3. Compared with the outside surface temperature of the trapezoidal section roller, theoutside surface temperature of the trapezoidal section roller is more even and higher. But thestructure of double inlets and outlets roller is more complex and require large flow rate. To some extent, it still be affected by the roller steering.4. By changing the runner of the original single spiral groove runner roller, theuniformity of temperature distribution of the outside surface of the roller was improvedperfectly. This program is not only easy to operate, and the effect is remarkable. So it is thebest choice to improve the temperature field of the roller.