 Subjects -> SOCIOLOGY (Total: 553 journals)
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- Determining Hydraulic Ram Pump Feasibility
Authors: Maxwell Pawlick; David Vaughn, Jeffery Plumblee
Abstract: Hydraulic ram pumps have been used for over 200 years to pump water using only the potential energy of elevated water. Today, the low price and simplicity of the materials and methods required to construct ram pumps make them an excellent option for small and mid-sized water systems in developing countries where elevated water is available. However, ram pumps are risky to implement because they will fail to deliver water if they are not designed correctly. Evaluating pump designs requires complex computer modeling typically unavailable in developing countries. Existing design documents for users without a specialization in fluid mechanics use vague rules of thumb to simplify the design process. Unfortunately, these rules cannot reliably predict whether or not a ram pump will deliver water in many cases. Recent research has focused on developing pump efficiency equations from non-dimensional analyses of experimental data, developing guidelines to optimize designs, and modeling ram pump function with numerical methods. Currently, the literature has not provided the typical designer with accurate and accessible methods for predicting the maximum delivery head or the delivery flowrate of a specific design. This study models the acceleration of fluid in the drive pipe and the intensity of the pressure spike to determine the feasibility of a wide variety of ram pump designs with a higher degree of certainty than previous rules of thumb. The model can be used in a Matlab program that determines if a design will function based on design parameters input by the user. The Matlab method was used along with conservative assumptions to predict the minimum design characteristics required for several common scenarios for easy reference. This work will allow a wider proliferation of hydraulic ram pumps through more accurate design tools, and reduce the cost of water systems for small developing communities.
PubDate: Mon, 22 Aug 2022 07:05:59 +000
- A case for gridshell structures in humanitarian assistance and disaster
relief efforts
Authors: Thomas Imhoff; Samar Malek
Abstract: This article focuses on the core concerns of shelter and settlement, and more specifically will focus on large-span shelters in humanitarian assistance and disaster relief (HA/DR) efforts. Furthermore, this article will introduce the audience to novel large-span structures called gridshells. This paper presents a parametric, computational study that quantifies the efficacy of bracing orientation and arrangement on the load carrying capacity of gridshells. The varied parameters include the grid density (“16 by 16” to “30 by 30”) and the bracing scheme (unbraced, continuous fully-braced, discontinuous fully-braced, continuous half-braced, and discontinuous half-braced). Four load cases were analyzed, namely a symmetric distributed load, an asymmetric distributed load, a centered point load, and an off-centered point load. The results of study provide designers with trends and basic design options upon which they can base further analysis depending on the requirements of the final structure.
PubDate: Tue, 19 Jul 2022 00:00:00 +000
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