# Numerical Simulation of Cavitation Erosion Aggressiveness Induced by Unsteady Cloud Cavitation
## 3 Results
### Influence of Cavitation Model
Consequently, it can concluded that the [PERSON] and Sauer models provide similar predictions of the erosion power in terms of erosion aggressiveness and location from cycle to cycle, while the [PERSON] model provides results that differ from cycle to cycle. Figure 12 represents compares the values of \(P_{tot\_load}\) without setting any threshold value for two consecutive shedding cycles obtained with the three cavitation models. With the Zwart model, a similar shape and amplitude of the \(P_{tot\_load}\) distribution is found in both cycles although the second one gives a slightly higher intensity. With the Sauer model, the two cycles show exactly the same result. In contrast, with the [PERSON] model a significant difference is found in the second half of the chord. More specifically, \(P_{tot\_load}\) drops with a faster rate towards a very small amplitude at 80% of the chord during the second cycle, meanwhile \(P_{tot\_load}\) decreases more gradually and it is still significant even at the trailing edge during the first cycle. Note that similar differences between two consecutive cycles are also observed along the 10 cycles shown in Figure 5 for all the cavitation models. Figure 11: Results obtained with the [PERSON] (**left**), [PERSON] (**middle**) and [PERSON] (**right**) models at instant \(T/T_{ref}=0.5\) comprising contours of \(\dot{m}\) from vapor to water (**top**) and contours of power density and value of the power load on the surface along the chord (red line in bottom graphs). Black isolines of \(\alpha_{v}=0.1\) showing the location of the main vapor cavities at each instant. Figure 12: Comparison of \(P_{tot\_load}\) distribution obtained for the first (black line) and second (red line) shedding cycles with the different cavitation models. Another conclusion that can be extracted from Figure 12 is that the cavitation model also influences the erosion distribution along the chord. More specifically, all three models give the maximum values of \(P_{tot\_load}\) around 40% of the chord at the attached cavity closure region but they give different results at the cloud cavity collapse region. With the [PERSON] model, the collapses of the clouds, shown on the left hand side of Figure 10, are less intense and they take place close to the trailing edge presenting a low amplitude of \(P_{tot\_load}\) from 50 to 100% of the chord. With the [PERSON] model, the cloud collapses are concentrated from 50 to 60% of the chord and the results show a small peak around 55% of the chord. With the Kunz model, the results are sensitive to the shedding cycle being considered. According to the experimental results presented in Figure 2, the main eroded area was located from 30 to the 70% of the chord and the maximum erosion was found from 40 to 50% of the chord. Based on these results, it can be concluded that the cavitation power distribution predicted by the Sauer model agrees more precisely with the experimental observations. Based on the previous discussion, it can be stated that different cavitation models give different results of cavitation aggressiveness regarding the condensation \(\hat{m}\), which determines the level of \(P_{den}\), and regarding the cavity topology, which determines the efficiency of the transmission from \(P_{den}\) to \(P_{load}\) on the surface and the size and location of the area subjected to the highest \(P_{tot\_load}\). Nonetheless, it can be concluded that the Sauer model give a more accurate prediction of cavitation aggressiveness than the rest.