Experimental Analysis of Water Flow in Aquaponics Fish Tanks

2019 ◽  
Author(s):  
Hannah Thomas ◽  
Danielle Coombs ◽  
Ivaylo Nedyalkov ◽  
Todd Guerdat
Keyword(s):  
Numerical Simulations ◽  
Water Flow ◽  
Experimental Analysis ◽  
Local Community ◽  
Small Scale ◽  
Acoustic Doppler Velocimeter ◽  
Operational Costs ◽  
Initial Cost ◽  
Fish Tank ◽  
Fish Tanks

Abstract Aquaponic systems are a combination of hydroponics, growing plants in water, and aquaculture, growing of fish. The two subsystems are connected so that the water circulating between the two, transfers the waste from the fish tank to the plants, where the plants take in nutrients. The water is filtered by the plants and is recirculated back into the fish tank. Small-scale aquaponic systems are of particular interest, as they are appropriate for rural and developing locations to harvest both plants and fish for a local community. To improve the level of sustainability, the flow within the fish tank needs to be better understood since most of the power required to operate an aquaponic system is used by the fish-tank pump. The shape of the fish tank is of importance for the flow in the tank and the initial cost of the tank. In this work, the flow in a 2 m × 2 m square fish tank with curved corners was studied experimentally with a Vectrino Acoustic Doppler Velocimeter. Two inlet configurations were studied and compared to each other — inlets at each corner of the tank, and inlets at two of the corners of the tank. The results suggest that good recirculation can be achieved with the two inlet locations. The present work can be used for evaluating numerical simulations of the flow in the tank. The ultimate goal of the study is to develop an inlet-design configuration which minimizes initial and operational costs of the small-scale aquaponic system.

An Experimental Analysis on Hydraulic Lifting of Solids through a Small-scale Vertical Tube

2000 ◽  
Vol 3 (1) ◽  
pp. 42-48 ◽  
Author(s):  
Chi Ho Yoon ◽  
Ou Kwang Kwon ◽  
Kwang Soo Kwon ◽  
Seok Ki Kwon ◽  
Dong Kil Lee
Keyword(s):  
Experimental Analysis ◽  
Vertical Tube ◽  
Small Scale

Aircraft applications of insecticides in East Africa

1961 ◽  
Vol 52 (2) ◽  
pp. 293-303 ◽  
Author(s):  
R. Foster ◽  
P. J. White ◽  
D. Yeo
Keyword(s):  
Meteorological Conditions ◽  
Small Scale ◽  
Central Province ◽  
Biological Factors ◽  
Cent Solution ◽  
Glossina Morsitans ◽  
Operational Costs ◽  
Low Volume ◽  
Aircraft Application ◽  
Savannah Woodland

SummaryFollowing successful small-scale trials, an attempt was made, by aircraft application of insecticide, to eradicate Glossina morsitans Westw. and G. pallidipes Aust. from an isolated block of savannah woodland, approximately 11 sq. miles in extent, at Chungai in the Central Province of Tanganyika between July 1958 and January 1959. A single-engined aircraft, fitted with two belt-driven rotary-cage atomisers, was used to apply a 5 per cent, solution of γ BHC in power kerosene at a nominal dosage of 0·08 gal. per acre (0.04 lb. γ BHC per acre). Seven applications were made at approximately 28-day intervals, the time taken to complete an application varying from five to eight days. The operation failed to control the flies. Although each of the first two applications reduced the apparent density of G. morsitans by about 90 per cent, and that of G. pallidipes by a lesser, although still considerable, factor, later applications gave varying and often low mortalities, and the populations increased slowly for some time, the insecticide applications causing only temporary depressions in numbers. Numbers fell towards the end of the operation, but final reductions were only about 50 per cent, or less. Kills of female flies were low, and this undoubtedly led to the eventual failure.The low volume-dosage, a drop spectrum that possibly contained too few droplets of the required size, meteorological conditions, and biological factors that apparently favoured the survival of female flies are suggested as contributory elements to the low mortalities.Operational costs were considerably lower than in previous work.

Experiments and Numerical Simulations of Water Flow over a Slit Weir for Measuring Very Small Discharges at River Intakes

2021 ◽  
Author(s):  
Daniela-Elena Gogoase Nistoran ◽  
Stefan-Mugur Simionescu ◽  
Nicoleta-Octavia Tanase
Keyword(s):  
Numerical Simulations ◽  
Water Flow

2D and 2.5D Numerical Simulations for Vortex-Induced Vibration (VIV) of a 1.5:1 Rectangular Cylinder

2021 ◽  
Author(s):  
Bowen Yan ◽  
Yangjin Yuan ◽  
Dalong Li ◽  
Ke Li ◽  
Qingshan Yang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Numerical Simulations ◽  
Phase Difference ◽  
Vortex Shedding ◽  
Lift Force ◽  
Small Scale ◽  
Aerodynamic Damping ◽  
Displacement Response ◽  
Wind Speeds ◽  
Rectangular Cylinder

The semi-periodic vortex-shedding phenomenon caused by flow separation at the windward corners of a rectangular cylinder would result in significant vortex-induced vibrations (VIVs). Based on the aeroelastic experiment of a rectangular cylinder with side ratio of 1.5:1, 2-dimensional (2D) and 2.5-dimensional (2.5D) numerical simulations of the VIV of a rectangular cylinder were comprehensively validated. The mechanism of VIV of the rectangular cylinder was in detail discussed in terms of vortex-induced forces, aeroelastic response, work analysis, aerodynamic damping ratio and flow visualization. The outcomes showed that the numerical results of aeroelastic displacement in the cross-wind direction and the vortex-shedding procedure around the rectangular cylinder were in general consistence with the experimental results by 2.5D numerical simulation. In both simulations, the phase difference between the lift and displacement response increased with the reduced wind speed and the vortex-induced resonance (VIR) disappeared at the phase difference of approximately 180∘. The work done by lift force shows a close relationship with vibration amplitudes at different reduced wind speeds. In 2.5D simulations, the lift force of the rectangular cylinder under different wind speeds would be affected by the presence of small-scale vortices in the turbulence flow field. Similarly, the phase difference between lift force and displacement response was not a constant with the same upstream wind speed. Aerodynamic damping identified from the VIV was mainly dependent on the reduced wind speed and negative damping ratios were revealed at the lock-in regime, which also greatly influenced the probability density function (PDF) of wind-induced displacement.

Water flow drives small scale biogeography of pesticides and bacterial pesticide degraders - A microcosm study using 2,4-D as a model compound

2018 ◽  
Vol 127 ◽  
pp. 137-147 ◽  
Author(s):  
Marc Pinheiro ◽  
Holger Pagel ◽  
Christian Poll ◽  
Franziska Ditterich ◽  
Patricia Garnier ◽  
...  
Keyword(s):  
Water Flow ◽  
Model Compound ◽  
Small Scale ◽  
Microcosm Study

Metal Flow and Die Filling in Coining of Micro Structures with and without Flash

2005 ◽  
Vol 6-8 ◽  
pp. 631-638 ◽  
Author(s):  
M. Thome ◽  
Gerhard Hirt ◽  
B. Rattay
Keyword(s):  
Numerical Simulations ◽  
Sheet Metal ◽  
Metal Forming ◽  
Production Systems ◽  
Metal Flow ◽  
Small Scale ◽  
Die Filling ◽  
Metal Plates ◽  
Micro Structures ◽  
Channel Structures

The continuing miniaturization of production systems and products poses a challenge for metal forming technologies to produce precise small scale products with microscopic geometric details. Thin metal plates with channel structures are considered to be typical examples for microfluidic applications [1,2]. In this study the coining process of sheet metal to produce channel and rib structures is examined in terms of geometrical die parameters and tool design. For this reason extensive experimental series and numerical simulations have been realized and evaluated.

scholarly journals Stakeholder consultations on small-scale irrigation schemes’ constraints in Zimbabwe

2021 ◽  
Author(s):  
Edgar Muhoyi ◽  
Josue Mbonigaba
Keyword(s):  
Local Community ◽  
Theory Of Constraints ◽  
Small Scale ◽  
Focus Group Discussions ◽  
Group Discussions ◽  
Key Informant ◽  
Technical Issues ◽  
Social Environmental ◽  
Political Economic ◽  
Small Scale Irrigation

AbstractSmall-scale irrigation schemes (SSIS) have been considered a solution to viability challenges in drought-stricken farming areas in developing countries. However, the schemes face severe constraints. In this paper, relevant constraints are identified and ranked in terms of how serious the limitations are from the perspective of stakeholders in drought-prone areas of the Chipinge District in Zimbabwe. Information for the study was gained through a questionnaire and focus group discussions with small-scale irrigation farmers as well as key informant interviews with government irrigation officials, irrigation managers and members of the local community leadership. The information was garnered between August and December in 2017 with the analysis conducted using descriptive statistics and thematic analysis, guided by the Theory of Constraints and classified in the political, economic, social, technological, environmental and legal (PESTEL) framework. Results indicated that SSIS are important in the drought-prone areas of the Chipinge District regarding food security and income generation. However, technical issues bedevilling the schemes are considered to be the most challenging limitations. The most important constraints—ranked in descending order of gravity—are technical, economic, social, environmental, legal and political challenges. Based on these findings, the research strongly recommends modernising small-scale irrigation schemes’ infrastructure, among other issues, as a priority in Zimbabwe's drought-prone areas.

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