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A new coupled model is developed to simulate the interaction between fluid droplet collisions on discrete particles (DPs) by using mathematic function.

In this model, the smoothed particle hydrodynamics (SPH) is used based on the kernel function and the time step which takes into consideration to the fluid domain in accordance with the discrete element method (DEM) with resistance function. The interaction between fluid and DPs consists of three parts, which are repulsive force, viscous shear force and attractive force caused by the capillary action. The numerical simulation of droplet collision on DPs presents the whole process of droplet motion. Otherwise, an experimental data were conducted to record the realistic process for verification.

The comparison result indicated that the numerical simulation is capable of capturing the entire process for droplet collision on DPs.

However, based on the difference of experimental environment, type of the DP and setups, the maximum spreading dimeters of could not fit the experimental data exactly.

In sum, the coupled SPH-DEM method simulation shows that the coupled model of SPH-DEM developed an entire effectiveness process for fluid–solid interaction problem.

A new roller compacted concrete dam of Fengman hydropower station was determined to be built in the toe of the old dam which had been identified as a dangerous dam. The new dam during construction would be impacted by the high‐speed flow discharged from the old dam. This is an important problem met for the first time in China, which would affect the whole project construction. The purpose of this paper is to describe a series of erosion experiments of the new dam material.

A kind of high‐speed flow erosion test apparatus was developed for erosion experiment of the new dam material. The maximum jet velocity was up to 40 m/s and the section area of the nozzle was 25 cm². In the process of experiments, the equipment showed its good performance. Erosive wear tests of two types of materials used in the new dam, a roller compacted concrete and a distorted concrete with four kinds of ages were carried out with the flow velocity in the range of 30‐35 m/s.

Erosion parameters and erosion laws of the two types of concretes with different ages were obtained, and a general relationship had been found between erosion rate and flow velocity: with velocity exponent between 3.33 and 3.93. It was also concluded that the erosion resistance of the distorted concrete was better than that of the roller compacted concrete and the mechanics properties of the concretes of over 14 days age was influenced slightly by water impacted.

The test results would play a practical technique guide role for the safety of this project during construction in the flood season.

The buried pipe element method can be used to calculate the temperature of mass concrete through highly efficient computing. However, in this method, temperatures along cooling pipes and the convection coefficient of the cooling pipe boundary should be improved to achieve higher accuracy. Thus, there is a need to propose a method for improvement.

According to the principle of heat balance and the temperature gradient characteristics of concrete around cooling pipes, a method to calculate the water temperature along cooling pipes using the buried pipe element method is proposed in this study. By comparing the results of a discrete algorithm and the buried pipe element method, it was discovered that the convection coefficient of the cooling pipe boundary for the buried pipe element method is only related to the thermal conductivity of concrete; therefore, it can be calculated by inverse analysis.

The results show that the buried pipe element method can achieve the same accuracy as the discrete method and simulate the temperature field of mass concrete with cooling pipes efficiently and accurately.

This new method can improve the calculation accuracy of the embedded element method and make the calculation results more reasonable and reliable.

The multi-scale numerical simulation method, able to represent the complexity of the random structures and capture phase degradation, is an effective way to investigate the long-term behavior of concrete in service and bridges the gap between research on the material and on the structural level. However, the combined chemical-physical deterioration mechanisms of concrete remain a challenging task. The purpose of this paper is to investigate the degradation mechanism of concrete at the waterline in cold regions induced by combined calcium leaching and frost damage.

With the help of the NIST’s three-dimensional (3D) hydration model and the random aggregate model, realistic 3D representative volume elements (RVEs) of concrete at the micro-, the meso-, and the macro-scales can be reconstructed. The boundary problem method is introduced to compute the homogenized mechanical properties for both sound and damaged RVEs. According to the damage characteristics, the staggering method including a random dissolution model and a thermo-mechanical coupling model is developed to simulate the synergy deterioration effects of interacted calcium leaching and frost attacks. The coupled damage procedure for the frost damage process is based on the hydraulic pressure theory and the ice lens growth theory considering the relationship between the frozen temperature and the radius of the capillary pore. Finally, regarding calcium leaching as the leading role in actual engineering, the numerical methodology for combined leaching and frost damage on concrete property is proposed using a successive multi-scale method.

On the basis of available experimental data, this methodology is employed to explore the deterioration process. The results agree with the experimental ones to some extent, chemical leaching leads to the nucleation of some micro-cracks (i.e. damage), and consequently, to the decrease of the frost resistance.

It is demonstrated that the multi-scale numerical methodology can capture potential aging and deterioration evolution processes, and can give an insight into the macroscopic property degradation of concrete under long-term aggressive conditions.

A method for optimizing net positive suction head required of axial‐flow pumps has been proposed by the present author, which is based on the two‐dimensional potential flow model and without considering the tip gap effect. The objective of the paper is to confirm if the method is just and feasible for the case of viscous fluid flow in impellers with tip gap.

A series of steady, three‐dimensional, noncavitating and cavitating, turbulent, incompressible flows of water through two axial‐flow pump impellers were calculated by using CFD code Fluent. The two impellers included a reference one with constant circulation at outlet and an optimized one with variable circulation designed with the author's method and code. In computations, the throttling and unthrottling approaches were used, respectively. Comparison of hydraulic performance, averaged flow variables at the impeller inlet and exit, flow in the tip gap, flow variables on blade surfaces and suction performance between the optimized and reference impellers was made.

It was confirmed that the optimized impeller has better hydraulic and suction performances. The method for optimizing with variable flow circulation profile along blade span at the outlet to impeller is proper and practical. Additionally, an unstable regime in the head curves of two impellers is presented. In the regime, a stall occurs on the pressure side of the blade and a hysteresis exists, which causes a hysteresis‐loop.

The effect of suction entry on flow is represented approximately by using a free‐vortex and uniform axial velocity. The diffusing component behind the impellers is not taken into account. The unsteadiness of flow is not considered, which would have a connection with stall pattern in an axial‐flow impeller.

The hydraulic and suction performances and flow variables of two axial‐flow pump impellers with tip clearance are obtained successfully with CFD. Stall and hysteresis as well as hysteresis‐loop in head curve are observed by using throttling and unthrottling approaches.

There is a growing concern in recent years regarding climate change risks to real estate in the developed and developing countries. It is anticipated that the property sector could be affected by variable climate and related extremes as well as by the strategies adopted to combat greenhouse gas (GHG) emissions. This paper aims to analyse the current knowledge regarding future climate changes to understand their possible impacts on the real estate sector of Malaysia with an aim to help stakeholders to adopt necessary responses to reduce negative impacts.

Available literature is reviewed and data related to climatic influences on buildings and structures are analysed to understand the climate change impacts on real estate in Malaysia.

The study reveals that temperature in the Peninsular Malaysia will increase by 1.1 to 3.6°C, rainfall will be more variable and river discharge in some river basins will increase up to 43 per cent during the northeast monsoon season by the end of this century. These changes in turn will pose risks of property damage and increase property lifecycle costs. Furthermore, property prices and the overall growth of the property sector may be affected by the government policy of GHG emission reduction by up to 45 per cent by the year 2030. This study concludes that the property sector of Malaysia will be most affected by the implementation of GHG emission reduction policy in the short term and due to the physical risk posed by variable climate and related extremes in the long term.

The study in general will assist in guiding the operational responses of various authorities, especially in terms of those interventions aimed at climate change risk reduction in the property sector of Malaysia.

The purpose of this paper is to develop a numerical method to model the simultaneous propagation of multiple hydraulic fractures (HFs) with fluid lags driven from a horizontal wellbore.

Fracture propagation in solid medium is modeled with the extended finite element method and fluid flow is modeled with finite volume method. Three iteration loops are introduced to solve the nonlinear system within each time increment, i.e. a Newtonian iteration to solve the solid-fluid coupling system, a Picard iteration to determine fluid front positions and a secant iteration to update fracture lengths.

The propagation of one single HF with a fluid lag is simulated and agrees well with semi-analytical solutions or other numerical results in the literature. The simultaneous propagation of two HFs are then investigated, which demonstrates the ability of the proposed method in capturing the hydraulic fracturing process with multiple fractures and fluid lags.

With the proposed method, one can simulate the simultaneous propagation of multiple HFs with fluid lags, which play a significant role during early-time propagation or when the confinement stress is relatively low (shallow HFs). Solid deformation and fracturing, fluid flow in fractures and in the wellbore are fully coupled, and three iteration loops are introduced to solve the nonlinear system.

The purpose of this paper is to analyze the potential for implementing Sustainable Development Goals (SDGs) into the civil engineering bachelor degree in the School of Civil Engineering at Universitat Politècnica de València (Spain).

All the 2019/2020 course syllabi were analyzed to diagnose at which extent each subject within the program curriculum contributes to achieving the different SDGs.

The results show a promising starting point as 75% of the courses address or have potential to address targets covering the 2030 Agenda. This paper also presents actions launched by the School of Civil Engineering to boost the SDGs into the civil engineering curriculum.

This paper presents a rigorous and systematic method that can be carried out in different bachelor degrees to find the subjects that have the potential to incorporate the SDGs into their program. This paper also presents actions launched by the Civil Engineering School to boost the SDGs into the civil engineering curriculum.

Cavitation erosion has always been a common technical problem in a hydraulic discharging structure. This paper aims to investigate the cavitation erosion behavior of hydraulic concrete under high-speed flow.

A high-speed and high-pressure venturi cavitation erosion generator was used to simulate the strong cavitation. The characteristics of hydrodynamic loads of cavitation bubble collapse zone, the failure characteristics and the erosion development process of concrete were investigated. The main influencing factors of cavitation erosion were discussed.

The collapse of the cavitation bubble group produced a high frequency, continuous and unsteady pulse load on the wall of concrete, which was more likely to cause fatigue failure of concrete materials. The cavitation action position and the main frequency of impact load were greatly affected by the downstream pressure. A power exponential relationship between cavitation load, cavitation erosion and flow speed was observed. With the increase of concrete strength, the degree of damage of cavitation erosion was approximately linearly reduced.

After cavitation erosion, a skeleton structure was formed by the accumulation of granular particles, and the relatively independent bulk structure of the surface differed from the flake structure formed after abrasion.

This paper presents part of the results of ongoing integrated and interdisciplinary studies conducted at a vulnerable coastal lagoon system with the aim of protecting it from further anthropogenic pollution. The target area is in southwestern Turkey, consisting of a lake that joins the Mediterranean Sea via a lagoon channel system. Land resources in the watershed are identified, including all the elements of the physical environment that influence potential land‐use, and are illustrated by the application of geographical information systems through mapping and visualization of various thematic layers of land. This study will enlighten those working on lagoon watersheds aiming at conservation of natural resources since it states the results of the studies conducted so far through various disciplines, and presents how data are utilized by the groups in an integrated manner. Based on the available data, pre‐modelling studies on hydrodynamic modelling and on water quality modelling are also referred. Identification of a watershed depends on gathering satisfactory data, which will further be used to establish sustainable development and management plans, apart from utilizing the obtained data for watershed and hydrodynamic modelling approaches and to better understand such complex systems.