## 4 Conclusions  
The primary purpose of the study was to evaluate the impact of alteration in step geometry on flow parameters such as pressure and energy dissipation across the stepped spillway model using the latest CFD (computational modelling dynamics) software package FLOW3D. * Total energy dissipations and pressure profiles were calculated for each of simulation. No increment in energy dissipation was obtained expect for lower flow rates like 0.020 m\({}^{3}\)/s where it increased to three percent in curved risers stepped spillways as compared to simple stepped spillways. * In a simple stepped spillway, the lower steps, such as step nos. 12, 13, and 14 were dissipating more energy as compared to higher steps. Moreover, this shifted to higher steps in the case of stepped spillways having curved risers. * Pressure profiles, along the vertical surface of steps in the case of simple stepped spillways, and along curved risers in the case of curved stepped spillways, showed that simple stepped spillway possess more negative pressure values as compared to curved stepped spillways. This can cause more cavitation in the case of simple stepped spillways as compared to curved stepped spillways, when the local pressure across the step face decreases less than the vapor pressure of water. _Police Recommendations_
* This research was conducted through the latest CFD commercial code FLOW3D. Though the calibration process provides enough accuracy through the use of fine grids, there is still possibility for inaccuracies. The finer meshing and the use of second-order advection options can be utilized in FLOW3D to find inaccuracies. * Spillway models with curved risers demonstrate an increment of three percent energy dissipation for lower flow rates. These types of spillways can be utilized for dams that are subject to continuous low emissions. Compared with a simple stepped spillway, the curved risers efficiently diminish material costs and allow more energy dissipation. * Spillways with curved risers do not significantly increase energy dissipation for high flow rates. Compared with simple stepped spillways, they dissipate almost the same amount of energy. It is important to use these types of flow rates instead of simple stepped spillways because they can save material costs, but can dissipate the same amount of energy. * Cavitation is an important parameter studied by dam spillway researchers. The spillways of many dams have been damaged by cavitation. Current research has identified that simple stepped spillways have more negative pressure than spillways with curved risers. The practical use of stepped spillways with curved risers can reduce the possibility of cavitation because they dissipate the same amount of energy. * The present research shows that the steps that consume more energy are experiencing more negative pressure. Thus, specific steps that dissipate more energy are more susceptible to cavitation. The energy dissipation distribution of the steps can be used to analyze the number of steps that consume more energy and endure more negative pressure. This fact is very useful in a practical sense because more resources can be utilized to build steps that dissipate more energy and are more prone to cavitation than steps that dissipate less energy and are less likely to occur[PERSON] This can help the design of the spillway in the future, and can stimulate the life of the spillway. Conceptualization, N.u.S. and M.A. ; methodology, N.u.S., M.A; software, N.u.S. ; validation, M.A., N.u.S. ; formal analysis, N.u.S., M.A. ; investigation, M.A. and N.S resources, N.u.S. ; data curation, N.u.S., M.A; writing--original draft preparation, N.u.S. and M.A; writing--review and editing, A.A. ([PERSON]) and M.M. ; visualization, A.A. ([PERSON]); supervision, H.P., G.O. ; project administration, H.P. ; funding [PERSON], H.P. All authors have read and agreed to the published version of the manuscript. **Funding:** This paper was supported by the Second Tibetan Plateau Scientific Expedition and Research Program (STEP) (Grant No.