**4. Verification of effectiveness by casting experiments**

Casting experiments were conducted to verify the effectiveness of the optimally designed residue trap.

**Figure 11.** *Cross section of capstan drum for experiments.*

**Figure 12.**

*Evaluation of foam residue defect for casting without foam residue trap. (a) Experimental result. (b) Flow analysis result.*

**83**

**Figure 13.**

**Figure 14.**

*(b) Flow analysis.*

*CFD Optimization Method to Design Foam Residue Traps for Full Mold Casting*

In this study, two types of capstan drums were cast: one with a conventional method without a residue trap and the other with an optimized residue trap method. The temperature of the metal was set to 1623 K, and the other conditions were the same as in the experiments in Section 2. After casting and cooling, the product was cut to make a test specimen, and the cut surface was color-checked to compare the defects. As shown in **Figure 11**, the position where the product part was cut was set to a horizontal plane 10 mm downward from the top of the rim

*Evaluation of foam residue defect in foam residue trap. (a) Experimental result. (b) Flow analysis result.*

*Evaluation of foam residue defect for casting with shape-optimized foam residue trap. (a) Experimental result.* 

The experimental results of the conventional plan and the corresponding simulation results are shown in **Figure 12**. This result suggests that this was caused by the residue of the foam model generated during the filling of the molten metal and remaining in the rim of the drum. The simulation results in **Figure 12(b)** indicate that residue defects are more likely to occur around the specimen, although the

**Figure 13** shows the experimental results of a residue trapping method using the

because the residue tends to accumulate on the top of the rim.

simulation does not fully predict the distribution of residue.

optimal shape and the corresponding simulation results.

*DOI: http://dx.doi.org/10.5772/intechopen.95505*

*CFD Optimization Method to Design Foam Residue Traps for Full Mold Casting DOI: http://dx.doi.org/10.5772/intechopen.95505*

#### **Figure 13.**

*Casting Processes and Modelling of Metallic Materials*

designed residue trap.

**Figure 11.**

*Cross section of capstan drum for experiments.*

In the conventional gating system, the metal flow shows that the residue is spreading inside the rim, and it is thought that the following factors influence the development of residue defects. The volume fraction of the residue in this case was *J*1 = 1.013. On the other hand, the residue trapping method has an opening in the residue trap where the metal containing residue agglomerates, through which residue is effectively collected into the trap. The part of the rim that is not in contact with the residue trap suppresses the backflow of metal containing residue. Due to these effects, the optimal shape of the residue trap is efficient for collecting residue and effective for capturing residue. The volume fraction of residue is 0.6906, which

Casting experiments were conducted to verify the effectiveness of the optimally

is more than 30% lower than that of the conventional method.

**4. Verification of effectiveness by casting experiments**

*Evaluation of foam residue defect for casting without foam residue trap. (a) Experimental result.* 

**82**

**Figure 12.**

*(b) Flow analysis result.*

*Evaluation of foam residue defect for casting with shape-optimized foam residue trap. (a) Experimental result. (b) Flow analysis.*

**Figure 14.** *Evaluation of foam residue defect in foam residue trap. (a) Experimental result. (b) Flow analysis result.*

In this study, two types of capstan drums were cast: one with a conventional method without a residue trap and the other with an optimized residue trap method. The temperature of the metal was set to 1623 K, and the other conditions were the same as in the experiments in Section 2. After casting and cooling, the product was cut to make a test specimen, and the cut surface was color-checked to compare the defects. As shown in **Figure 11**, the position where the product part was cut was set to a horizontal plane 10 mm downward from the top of the rim because the residue tends to accumulate on the top of the rim.

The experimental results of the conventional plan and the corresponding simulation results are shown in **Figure 12**. This result suggests that this was caused by the residue of the foam model generated during the filling of the molten metal and remaining in the rim of the drum. The simulation results in **Figure 12(b)** indicate that residue defects are more likely to occur around the specimen, although the simulation does not fully predict the distribution of residue.

**Figure 13** shows the experimental results of a residue trapping method using the optimal shape and the corresponding simulation results.

Slight shrinkage nests were observed in the specimens, but no residue defects were observed. Similarly, in the simulation results, there was almost no residue around the specimen. Therefore, the residue traps were also cut in the same way as the test specimens, and the color inside each trap was checked. The results and the corresponding simulation results are shown in **Figure 14**. Residue defects were observed in the residue trap, indicating that the residue generated inside the product was captured well by the trap. Therefore, this study confirms that the residue trapping method using the optimal shape effectively reduces residue defects.
