Water supply systems need to be designed in an efficient way, accounting for both construction costs and operational energy expenditures when pumping is required. Since water demand varies depending on the moment’s necessities, especially when it comes to agricultural purposes, water supply systems should also be designed to adequately handle this. This paper presents a straightforward design methodology that using a constant flow rate, the total cost is equivalent to that of the variable demand flow. The methodology is based on the Granados System, which is a very intuitive and practical gradient based procedure. To adapt it to seasonal demand, the concepts of Equivalent Flow Rate and Equivalent Volume are presented and applied in a simple case study. These concepts are computationally straightforward and facilitate the design process of hydraulic drives under demand variability and can be used in multiple methodologies, aside from the Granados System. The Equivalent Flow Rate and Equivalent Volume offer a solution to design procedures that require a constant flow regime, adapting them to more realistic design situations and therefore widening their practical scope.

Water supply systems need to be designed accounting for both construction and operational costs. When the installation requires water pumping, it is key for the operational costs to know how well the pump can perform. So far, pump efficiency has been considered using conservative values, in the absence of a better estimation. The aim of this paper was to improve determining the energy costs by clarifying what the value of the pump performance should be. For this, 226 commercial pumps were studied, registering the efficiency at the optimum operating point, as well as other variables such as the flow rate, height, and pump type. As a result, a strong relationship between the pump performance and the discharge flow was spotted. That allowed the generation of an empirical curve, which can be used by designers to anticipate what pump efficiency can be expected. The results are used in a simple case study using the Granados Optimization System. These achievements can be implemented in design policies for a better energy assessment in the optimization of water supply systems.

This research aims to identify the number of pumps that should be working at any moment during the operation of a pumping station in order to provide the desired volume of water whilst consuming the least amount of energy. This is typically done by complex iterative algorithms that require much computational effort. The pumping station should pump the desired volume of water V* using the least specific energy e* (energy per volume). In the methodology of this article, the shape of the curves e*–V* was analyzed. The result is that such curves present a convex hyperbola shape. This is a straightforward analytic solution that does not require any iterations. The representation of the Convex Hyperbolas Charts will indicate the best pump combination during the operation of a pumping station. Therefore, this is a straightforward resource for practitioners: the curves immediately tell engineers the number of pumps that should be turned on, depending on the desired volume of water to pump. The elaboration of such charts only requires the use of any calculation sheet, only once, and it is a permanent resource that can be used at any time during the operation. In addition, the Convex Hyperbolas Charts are completely compatible and complementary with any other operation control technique.

<p>Natural soils are home to an enormous variety of microorganisms. Microbial transport is important for a wide range of natural and artificial processes. However, the transport and distribution of bacteria in water flow at porous scale is still to be fully understood.</p><p>The Biofilm is a collective structure of microorganisms and it is covered by a protective layer secreted by the microorganisms themselves. The objective of this study is to identify and characterize the Elemental Biofilm Architectures that develop in a porous medium crossed by a laminar flow. This is a process that frequently occurs in nature, when there is water flow through the soil.</p><p>In the case of this study, different flow velocities and the percentage of nutrients (% LB Broth diluted in water) were tested, as well as oxygen control. A non-flagellated fluorescent mutant bacterium of P.Putida was used to analyze bacterial and biofilm growth through a homogeneous porous medium. Also, two different methodologies were carried out during the experiments: Methodology A and B. With methodology A the bacteria were initially grown in the porous media, and then and bacterial free flow was injected at a constant flow rate. In methodology B, the porous media was initially free of bacteria, and a bacterial solution was injected at a constant flow rate during the experiment.</p><p>In the experiments, the results show different architectural formations such as streamers, chains, ripples and fine lines. With both methodologies, bacteria develop similar biofilm architectures, such as streamers and ripples; but distributed differently throughout the porous media. The biggest difference relies on the deposit profile: in Methodology A most of the biomass accumulates towards the outlet of the porous media, while for Methodology B towards the inlet.</p>

Título de la tesis: New design methodology for branched hydraulic networks that accounts for variable water demand and energy assessment.