To clarify the flow control mechanism of dimple surface and its influencing factors, this paper arranged cavity structures on suction a highly loaded compressor cascade. The Reynolds-averaged Navier–Stokes equations were utilized to calculate impact geometric structure inlet conditions characteristics effect surface. Additionally, stress-blended eddy simulation was employed compute unsteady vortex. By using Liutex vortex determination criterion, regimes (diffuser-confuser, horseshoe vortex,...

Abstract With the aim of unifying damping concept and evaluating amount in a structure, this paper investigates whether friction action can be equivalent to traditional viscous damping. The research focused on purely concave distribution cases, uniform their combination cases spring-friction isolation system. dynamic responses numerical method using were compared with those another methods under sine wave ground motions. comparison results shows that converted some errors by an equation....

Abstract In contrast to the traditional black box machine learning model, white model can achieve higher prediction accuracy and accurately evaluate explain results. Cavity water depth cavity length of aeration facilities are predicted in this research based on Extreme Gradient Boosting (XGBoost) a Bayesian optimization technique. The Shapley Additive Explanation (SHAP) method is then utilized This study demonstrates how SHAP may order all features feature interaction terms accordance with...

To promote the coordinated and sustainable development of hydropower exploitation ecological environment in upper reaches Yellow River, a fine simulation downstream riverway Yangqu Hydropower Station was carried out to analyze impact changes water depth flow velocity on fish habitats after impoundment Station. In this paper, Gymnocypris eckloni selected as target species. The habitat model constructed using MIKE21. quality species graded by fuzzy logic method with suitable conditions....

Abstract In this study, a support vector machine (SVM) and three optimization algorithms are used to develop discharge coefficient (Cd) prediction model for the semi-circular side weir (SCSW). After that, we derived input output parameters of by dimensionless analysis as ratio flow depth at crest point upstream diameter (h1/D), main channel width (B/D), height (P/D), Froude number (Fr), Cd. The sensitivity coefficients Cd were calculated based on Sobol's method. research shows that SVM...

Abstract In this paper, the discharge coefficient prediction model for structure in a subcritical flow regime is first established by extreme learning machine (ELM) and Bayesian network, model's performance analyzed verified detail. addition, global sensitivity analysis method introduced to optimal analyze dimensionless parameters affecting coefficient. The results show that (BELM) can effectively predict coefficients of symmetric stepped labyrinth side weir. range 95% confidence interval...

Piano key weirs (PKWs) have been introduced in recent years as a hydraulically efficient and cost-effective type of spillway, there are more than 30 PKWs under construction or already constructed globally. However, owing to the numerous geometric parameters complex hydraulic characteristics PKWs, discharge capacity PKW is still difficult estimate. To improve overall understanding flow behavior vicinity investigate intrinsic link between structural this study employs combination numerical...

Abstract In this paper, the sparrow search algorithm is used to predict discharge coefficient (Cd) of triangular side orifice for first time. Dimensionless parameters influencing size Cd orifices are obtained as input values and output model. The results show that determination R2 0.973, root means square error RMSE 0.0122, average absolute percentage 0.010% in testing phase. model has high forecast accuracy, strong generalization ability higher accuracy than other models traditional...

For flood discharge structures with high water heads, aeration facilities are usually installed in engineering to promote flow and prevent cavitation damage the overflow surface. Actual has shown that as slope of channel bottom decreases or level changes lead a decrease Froude number, cavity morphology after conventional allotype aerators is poor. This article proposes curved facility scheme based on idea locally increasing reduce impact angle, which formed by convex parabolic plate concave...

Abstract The development of hydroelectric projects has adversely affected the reproductive activities downstream fish species. To facilitate natural reproduction and restore spawning grounds post‐dam construction, it is imperative to explore ecological factors crucial for their reproduction. Currently, various research methods with different advantages limitations are employed this purpose. Using identified locations periods as clues, we quantitatively investigate flow velocity, water depth,...

Friction action is a damping mechanism used in civil structures. It often works together with traditional viscous damping. The rolling friction nonlinear, and its scaling process shaking table model tests suspect, especially cases of working combination dampers. To solve the problem, numerical simplified damper‐Coulomb base isolation system was scaled. comparison between scaled prototype results showed two important factors that influence action. One factor unscaled gravity acceleration,...

A dry, low-NOx (DLN) combustor for a heavy-duty gas turbine using lean premixed technology was studied. high-fidelity test model built the experimental study particle image velocimetry (PIV). The non-reacting flow in DLN combustion chamber investigated experimentally and numerically. numerical results are good agreement with data. show that recirculation zones were formed downstream of each swirl nozzle pattern section self-similar under different working conditions. For two adjacent nozzles...

The seismic isolation efficiency of different friction-based devices needs verification by shaking table test, but faces problems in scaling before the test due to their frictional nonlinearity. To solve problems, a simplified civil structure, isolated self-centering spring-friction device, was numerically scaled ways considering effect friction action. responses models were back those prototype and compared with prototype. solutions validated on simply supported bridges using pendulum...

The cavity length, which is a vital index in aeration and corrosion reduction engineering, affected by many factors challenging to calculate. In this study, 10-fold cross-validation was performed select the optimal input configuration. Additionally, hyperparameters of three ensemble learning models—random forest (RF), gradient boosting decision tree (GBDT), extreme (XGBOOST)—were fine-tuned Bayesian optimization (BO) algorithm improve prediction accuracy compare five empirical methods....

When the ground motion is input into a Spring-Viscous damping-Coulomb friction plane isolation system with XY shear keys along certain inclined angle, will be sheared asynchronously, which lead to structural violent curvilinear movement in plane, resulting coupling effect. In this paper, influence of on relative displacement response structure studied, and variation peak spring stiffness coefficient, damping constant coefficient analyzed detail, so as find optimal parameter design under The...

In the hydraulically suspended passive shutdown assembly, in order to prevent liquid suspension rod falling too fast and outer tube from violent impact, it is necessary study way increase flow resistance. This added grooves wall of narrow channel its Using RNG k-ε turbulence model Fluent, influence groove structure parameters Reynolds number on resistance was discussed find optimal parameters. The results showed that increased with concave–convex ratio, when ratio small, decreased thickness,...