WELDING RESEARCH A B Fig. 14 — Effective creep strain and maximum principal stress for EB welding. A — Effective creep strain; B — maximum principal stress. NOVEMBER 2016 / WELDING JOURNAL 437-s A cooling system was designed by modifying the new design of the furnace roll (Fig. 2A). The roll was enclosed by the journal welds, as shown in Fig. 7A. To allow air to flow into the roll, the journal at the right-hand side was redesigned to allow air flow into the roll through a center tube and out of the roll via the four holes around the center hole, as shown in Fig. 7B. A one-fourth heat transfer model and a CFD model (Fig. 8) were created for computational efficiency to evaluate the effect of the cooling design on the temperature of the roll shell by considering the symmetry of geometry, air flow, and heat convection on the roll. The heat transfer model has solid parts that include the roll shell wall and the journals. The outer surface of the roll shell was heated from the hot air in the furnace, as shown in Fig. 8. The CFD model includes the fluid that is air in this analysis. The temperature-dependent properties are shown in Table 2. The CFD boundary conditions include inlet pressure (0.62 MPa), outlet pressure (0.1 MPa), noslip/ no-penetration conditions at a wall, and air temperature at the inlet (37C). The inlet is the center hole and the outlet is the four holes, as shown in Fig. 6B. The analysis was conducted using the cosimulation capability of the ABAQUS/CFD module and the ABAQUS/standard module. ABAQUS /CFD simulated the air flow inside the roll and ABAQUS/standard modeled the heat transfer between the air and the roll and in the roll. For a small time increment, a CFD analysis was conducted to predict temperature, pressure, and velocity of the air and output heat flux in the interface between the air and the roll. A heat transfer analysis was conducted by inputting the heat flux from the CFD analysis to predict the temperature in the roll and output the temperature in the interface between the air and the roll. This analysis process was repeated until the end of the simulated time. Since each time increment was small, this coupled heat transfer and CFD analysis was computationally expensive. Therefore, a one-fourth model Fig. 15 — Temperature of the roll with inside cooling and outside heating. Fig. 16 — Predicted effective creep strain for ten loading cycles with inside cooling.
Welding Journal | November 2016
To see the actual publication please follow the link above