We talk with Prof. Corrado Gisonni, the IAHR’s division chair for Europe, on the organization’s activities and on how hydroengineering and hydraulics can help resolve current global problems.

The paper presents the influence of different liquid cargo properties on discharge rate of hydraulic submerged cargo pumps on modern product and chemical tankers is presented in the paper. Main parts of submerged cargo pumps and hydraulic drive system are described. Some examples of technical solutions of the described systems installed on board of the newly building constructed ship m/t ‘Helix’ are presented. The formula of use application of flow and drive characteristics of cargo pumps is given. These characteristics were made derived for a basic cargo (fresh water) for the case of the service of a real cargo of different viscosity and density.

The paper presents the results of simulation tests of hydraulic resistance and temperature distribution of the prototype Stirling alpha engine supplied with waste heat. The following elements were analyzed: heater, regenerator and cooler. The engine uses compressed air as a working gas. Analyses were carried out for three working pressure values and different engine speeds. The work was carried out in order to optimize the configuration of the engine due to the minimization of hydraulic resistance, while maintaining the required thermal capacity of the device. Preliminary tests carried out on the real object allowed to determine boundary and initial conditions for simulation purposes. The simulation assumes that there is no heat exchange between the regenerator and the environment. The solid model used in simulation tests includes the following elements: supply channel, heater, regenerator, cooler, discharge channel. Due to the symmetrical structure of the analyzed elements, simulation tests were carried out using 1/6 of the volume of the system.

The paper deals with calibration of the simulation models of hydraulic part of an irrigation project. Calibrated simulation model can be used in design, reconstruction, enlargement or maintenance of the pressurized irrigation systems. Computer model of the water distribution system is a valuable tool which can assist engineers and planners in analyzing the hydraulic performance of water delivery systems. Calibration of the water distribution model consists in comparison of pressures and flows predicted with observed pressures and flows for known operating conditions (i.e., pump operation, tank levels, pressure-reducing valve settings), and adjustment of the input data for the model to improve agreement between observed and predicted values. In practice, given a set or sets of measured state variables, engineers apply trial and error techniques with their judgment to vary the parameters and accomplish this task. Trial and error techniques are tedious do not guarantee reasonable results. The paper introduces the methodology of determination of calibrated parameters automatically. Described methodology of calibration is based on optimizing procedures using the harmony search approach.

Fly-ash is a form of production waste produced as a result of the burning of coal for energy production. Millions of tonnes of this waste are produced worldwide every year; hence it is extremely important to dispose of it in a useful way, including through treating the initial raw material to obtain a material of higher quality. The aim of the present work is to determine the suitability of processed fly-ash from lignite for reinforcing (stabilizing) soils used in the building of road foundations and embankments. The results provide a method of recycling this waste while at the same time obtaining new materials and technologies for use in road building. This is an important issue both environmentally and in terms of the positive effect that processed fly-ash can have on the stability of road structures.

This article presents the results of experiments carried out using fly-ash produced from lignite at the P¹tnów Power Plant. This ash was first modified (activated) using a Wapeco magnetic activator, and then used to produce hydraulic binders (with the addition of cement) and soil-binder mixtures. These mixtures were made using natural soils from seven different deposits in the Lubuskie region (western Poland). They were stabilized using two hydraulic binders (strength ratings 3 MPa and 9 MPa) added in different amounts (6% and 8% relative to the mass of the soil). During the experiment, a determination was made of the increase in the strength of the analysed samples (after 14, 28, and 42 days) and the increase in the bearing ratio (immediately after consolidation and after 7 days).

Interpretation of the results of the experiment made it possible to assess the dynamics of the increase in compression strength and load-bearing capacity of various soils stabilized with hydraulic binders produced from lignite ash, and to indicate possibilities for the use of these materials.

The analysis showed that it is possible to use these binders for the stabilisation of soils, enabling soils formerly considered to have weak load-bearing capacity (clayey sand; clayey, sandy gravel; clays) to be classified as fully usable in road construction.

Environmental hydraulics is a sub-branch of environmental fluid mechanics that deals with the movement of water and transport processes in both natural water bodies and engineered waterways. Techniques developed to evaluate flow resistance in man-made conduits can be successfully applied to natural waterways.

Careful study of river channel hydraulics is helping recover archeological treasures from the bottom of the Vistula River in Warsaw, lost by Swedish looters back in the seventeenth century.

The article presents the results of experimental research aimed at recognizing the impact of the design of energy dissipation devices on the formation of bed local scouring below the sluice gate. The experiments were carried out on a model of a sluice gate built in a rectangular flume with a width of 0.58 m, with the outflow of the stream from under the slider to a horizontal bed 0.80 m long. Behind the dam gate valve three different constructions of energy dissipation devices were used: flat, horizontal slab, slab equipped with baffle blocks arranged in two rows and rip-rap. The experiments assumed forming a scour hole in 480 minutes downstream the sluice, where the bed was filled with sorted sand. The depths of the scour were measured in the longitudinal profile after 30, 60, 90, 120, 180, 240, 300, 360, 420 and 480 minutes. The deepest scour holes of the bed, both in terms of depth and length, occurred on the structure model with energy dissipation devices made as a flat, horizontal plate. At the same time, in this case, the hole was developing the most rapidly, and its shape and size posed the greatest threat to the stability of the structure. The use of baffle blocks arranged in two rows or a rip-rap behind the structure slide noticeably reduced the size of the scour and delayed the erosion of the bottom in time, as compared to the course of this process on a model with a flat, horizontal slab.

The composite weir-gate structure is considered an important hydraulic structure. This is because of its widely used in civil engineering hydraulic works especially in an irrigation system to measure, control, divert and keep the required water level. This study focuses on the influence of barrier existence on the hydraulic parameters that described the hydraulic characteristics of composite weir-gate hydraulic structure. In this study, several experimental runs were conducted to determine the effect of barrier's location, spacing and number on the water level and depth at the downstream region of flume, discharge coefficient of composite hydraulic structure, and flow rate throughout the flume. Our experiments indicated that the turbulence intensity, inlet effect, and position, gap, and number of barriers have affected the hydraulic behavior of weir-gate structure. This appears clearly by obtaining different results of discharge coefficient and flow rate that cross the weir-gate structure comparing with same cases without barriers. Also this study gives some insights on the significance roles of fluid separation, eddies generation near the barrier, fluid resistance and overlap between overflow and underflow velocities and their effects on hydraulic factors that dominate the problem. These hydraulic factors must be considered in the design and construction of barrier/barriers in open channel to prevent any fluctuation or drop in discharge, water elevation and the required water depth at downstream region.