Nowadays, hydropower plays an essential role in the energy market. Due to their fast response and regulation capacity, hydraulic turbines operate at off-design conditions with a high number of starts and stops. In this situation, dynamic loads and stresses over the structure are high, registering some failures over time, especially in the runner. Therefore, it is important to know the dynamic r...

The water leak-off during hydraulic fracturing in shale gas reservoirs is a complicated transport behavior involving thermal (T), hydrodynamic (H), mechanical (M) and chemical (C) processes. Although many leak-off models have been published, none of the models fully coupled the transient fluid flow modeling with heat transfer, chemical-potential equilibrium and natural-fracture dilation phenome...

[1] This study presents a stochastic inverse method for aquifer structure identification using sparse geophysical and hydraulic response data. The method is based on updating structure parameters from a transition probability model to iteratively modify the aquifer structure and parameter zonation. The method is extended to the adaptive parameterization of facies hydraulic parameters by includi...

We investigated the role of increasingly well-constrained geologic structures in the subsurface (i.e., subsurface architecture) in predicting streambed flux and hyporheic residence time distribution (RTD) for a headwater stream. Five subsurface realizations with increasingly resolved lithological boundaries were simulated in which model geometries were based on increasing information about flow...

This paper studies the precision motion control of single-rod hydraulic actuators with time-varying unknown inertia loads. The swing motion control of a robot arm driven by a single-rod hydraulic actuator (a scaled down version of industrial backhoe loader arm) is used as a case study. During the swing motion, the eeective mass acting on the hydraulic actuator varies greatly with the swing angl...

Sediment erosion not only reduces efficiency and life of hydropower turbines but also causes problems in operation and maintenance. Several factors are responsible for this erosion in hydro turbine components. This paper presents the sediment erosion types in hydraulic turbines and their components based upon an extensive literature review and the field observation at Cahua hydropower plant, Pe...

The paper presents an application of a variance decomposition method for the sensitivity analysis of the thermal hydraulic (TH) model of the Passive Containment Cooling System (PCCS) of an Advanced Pressurized Reactor (AP1000). The Loss Of Coolant Accident (LOCA) is considered as the most representative accident for identifying the Failure Damage Domain (FDD) of the PCCS with respect to the ind...

1. The xylem pressure inducing 50% loss of hydraulic conductivity due to embolism (P50) is widely used for comparisons of xylem vulnerability among species and across aridity gradients. However, despite its utility as an index of resistance to catastrophic xylem failure under extreme drought, P50 may have no special physiological relevance in the context of stomatal regulation of daily minimum ...