scholarly journals A Laboratory Exercise on Dilution Ratio and Water Flow of a Venturi-type Proportioner

1992 ◽  
Vol 2 (1) ◽  
pp. 95-96
Author(s):  
David R. Hershey ◽  
Susan Sand

A Venturi-type proportioner (VP), trade name Hozon, can be used for an inexpensive, hands-on laboratory exercise that demonstrates the effect of water pressure on dilution ratio and water flow. Using electrical conductivity (EC) meters to determine solution concentration allows students to discover that the dilution ratio increases with water pressure, from 1:10 at 15 psi to 1:15 at 55 psi. The greater dilution at higher pressure can be explained by measuring the water flow, which is 2.3 gal/min (8.7 litersžmin-1) at 15 psi but 3.5 gal/min (13.2 litersžmin-1) at 55 psi. Experiments relating water pressure to dilution ratio provide experience in use and calibration of VPs and EC meters, as well as graph preparation and interpretation.

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 682
Author(s):  
Eko Surojo ◽  
Aziz Harya Gumilang ◽  
Triyono Triyono ◽  
Aditya Rio Prabowo ◽  
Eko Prasetya Budiana ◽  
...  

Underwater wet welding (UWW) combined with the shielded metal arc welding (SMAW) method has proven to be an effective way of permanently joining metals that can be performed in water. This research was conducted to determine the effect of water flow rate on the physical and mechanical properties (tensile, hardness, toughness, and bending effect) of underwater welded bead on A36 steel plate. The control variables used were a welding speed of 4 mm/s, a current of 120 A, electrode E7018 with a diameter of 4 mm, and freshwater. The results show that variations in water flow affected defects, microstructure, and mechanical properties of underwater welds. These defects include spatter, porosity, and undercut, which occur in all underwater welding results. The presence of flow and an increased flow rate causes differences in the microstructure, increased porosity on the weld metal, and undercut on the UWW specimen. An increase in water flow rate causes the acicular ferrite microstructure to appear greater, and the heat-affected zone (HAZ) will form finer grains. The best mechanical properties are achieved by welding with the highest flow rate, with a tensile strength of 534.1 MPa, 3.6% elongation, a Vickers microhardness in the HAZ area of 424 HV, and an impact strength of 1.47 J/mm2.


2003 ◽  
Vol 37 ◽  
pp. 281-285 ◽  
Author(s):  
Paul D. Bates ◽  
Martin J. Siegert ◽  
Victoria Lee ◽  
Bryn P. Hubbard ◽  
Peter W. Nienow

AbstractChannels incised into bedrock, or Nye channels, often form an important component of subglacial drainage at temperate glaciers, and their structure exerts control over patterns and rates of (a) channel erosion, (b) water flow-velocity and (c) water pressure. The latter, in turn, exerts a strong control over basal traction and, thus, ice dynamics. In order to investigate these controls, it is necessary to quantify detailed flow processes in subglacial Nye channels. However, it is effectively impossible to acquire such measurements from fully pressurized, subglacial channels. To solve this problem, we here apply a three-dimensional, finite-volume solution of the Reynolds averaged Navier– Stokes (RANS) equations with a one-equation mixing-length turbulence closure to simulate flow in a 3 m long section of an active Nye channel located in the immediate foreground of Glacier de Tsanfleuron, Switzerland. Numerical model output permits high-resolution visualization of water flow through the channel reach, and enables evaluation of the experimental manipulation of the pressure field adopted across the overlying ice lid. This yields an increased theoretical understanding of the hydraulic behaviour of Nye channels, and, in the future, of their effect on glacier drainage, geomorphology and ice dynamics.


2014 ◽  
Vol 1029 ◽  
pp. 176-181 ◽  
Author(s):  
Ion Aurel Perianu ◽  
Ion Mitelea ◽  
Viorel Aurel Şerban

In this paper research elements regarding the effect of water pressure variation on cut surfaces quality are presented in the field of abrasive water jet cutting of materials hard to process by machining such as austenitic stainless steels, in this case with a thickness of 20 mm. Selection of the optimal cutting process based on technical and economic criteria takes into consideration the type and thickness of the targeted material and also the physical and geometrical quality requirements. The present paper contains experimental research results regarding abrasive water jet cutting of austenitic stainless steel EN 1.4306 (ASTM 304 L) at different values of water pressure. The abrasive material used is Garnet with particle granulation 80 Mesh. By making roughness measurements and hardness examinations of the cut surface an evaluation will be made of the surface quality defining the optimal pressure values.


2015 ◽  
Vol 3 (3) ◽  
pp. 849-908 ◽  
Author(s):  
F. Beaud ◽  
G. E. Flowers ◽  
J. G. Venditti

Abstract. Bedrock erosion by sediment-bearing subglacial water remains little-studied, however the process is thought to contribute to bedrock erosion rates in glaciated landscapes and is implicated in the excavation of tunnel valleys and the incision of inner gorges. We adapt physics-based models of fluvial abrasion to the subglacial environment, assembling the first model designed to quantify bedrock erosion caused by transient subglacial water flow. The subglacial drainage model consists of a one-dimensional network of cavities dynamically coupled to one or several Röthlisberger channels (R-channels). The bedrock erosion model is based on the tools and cover effect, whereby particles entrained by the flow impact exposed bedrock. We explore the dependency of glacial meltwater erosion on the structure and magnitude of water input to the system, the ice geometry and the sediment supply. We find that erosion is not a function of water discharge alone, but also depends on channel size, water pressure and on sediment supply, as in fluvial systems. Modelled glacial meltwater erosion rates are one to two orders of magnitude lower than the expected rates of total glacial erosion required to produce the sediment supply rates we impose, suggesting that glacial meltwater erosion is negligible at the basin scale. Nevertheless, due to the extreme localization of glacial meltwater erosion (at the base of R-channels), this process can carve bedrock (Nye) channels. In fact, our simulations suggest that the incision of bedrock channels several centimetres deep and a few meters wide can occur in a single year. Modelled incision rates indicate that subglacial water flow can gradually carve a tunnel valley and enhance the relief or even initiate the carving of an inner gorge.


2020 ◽  
Vol 195 ◽  
pp. 03014
Author(s):  
Roberta Dainese ◽  
Giuseppe Tedeschi ◽  
Thierry Fourcaud ◽  
Alessandro Tarantino

The response of the shallow portion of the ground (vadose zone) and of earth structures is affected by the interaction with the atmosphere. Rainwater infiltration and evapotranspiration affect the stability of man-made and natural slopes and cause shallow foundations and embankments to settle and heave. Very frequently, the ground surface is covered by vegetation and, as a result, transpiration plays a major role in ground-atmosphere interaction. The soil, the plant, and the atmosphere form a continuous hydraulic system, which is referred to as Soil-Plant-Atmosphere Continuum (SPAC). The SPAC actually represents the ‘boundary condition’ of the geotechnical water flow problem. Water flow in soil and plant takes place because of gradients in hydraulic head triggered by the negative water pressure (water tension) generated in the leaf stomata. To study the response of the SPAC, (negative) water pressure needs to be measured not only in the soil but also in the plant. The paper presents a novel technique to measure the xylem water pressure based on the use of the High-Capacity Tensiometer (HCT), which is benchmarked against conventional techniques for xylem water pressure measurements, i.e. the Pressure Chamber (PC) and the Thermocouple Psychrometer (TP).


1999 ◽  
Vol 277 (6) ◽  
pp. S67 ◽  
Author(s):  
D W Rodenbaugh ◽  
H L Collins ◽  
C Y Chen ◽  
S E DiCarlo

We developed a laboratory exercise that involves the construction and subsequent manipulation of a model of the cardiovascular system. The laboratory was designed to engage students in interactive, inquiry-based learning and to stimulate interest for future science study. The model presents a concrete means by which cardiovascular mechanics can be understood as well as a focal point for student interaction and discussion of cardiovascular principles. The laboratory contains directions for the construction of an inexpensive, easy-to-build model as well as an experimental protocol. From this experience students may gain an appreciation fo science that cannot be obtained by reading a book or interacting with a computer. Students not only learn the significant physiological concepts but also appreciate the importance of laboratory experimentation for understanding complex concepts. Model construction provides a hands-on experience that may substantially improve performance in science processes. We believe that model construction is an appropriate method for teaching advanced concepts.


2013 ◽  
Vol 15 (3) ◽  
pp. 888-896 ◽  
Author(s):  
Songhao Wang ◽  
Ronald Garcia

The objective of this paper is to present the feasibility of a self-rechargeable digital water flow meter (SRDFM) system for water pipes using the latest data processing and wireless communication technologies while causing negligible water pressure drop (head loss). The system uses a Pelton turbine generator to power the electronic circuit, which processes and transmits the signals generated by several flow meters. ZigBee technology was used to process and send wireless signals. Signals from two water meters were acquired, processed, and transmitted with only one control/transmission unit during this study. The new system was assessed experimentally, reaching a maximum of 80 m of wireless transmittance distance at a minimum flow rate of 5 L/min for a 16-mm diameter pipe (self-charged).


2020 ◽  
Vol 14 (1) ◽  
pp. 287-308 ◽  
Author(s):  
Fabian Lindner ◽  
Fabian Walter ◽  
Gabi Laske ◽  
Florent Gimbert

Abstract. Hydraulic processes impact viscous and brittle ice deformation. Water-driven fracturing as well as turbulent water flow within and beneath glaciers radiate seismic waves which provide insights into otherwise hard-to-access englacial and subglacial environments. In this study, we analyze glaciohydraulic tremors recorded by four seismic arrays installed in different parts of Glacier de la Plaine Morte, Switzerland. Data were recorded during the 2016 melt season including the sudden subglacial drainage of an ice-marginal lake. Together with our seismic data, discharge, lake level, and ice flow measurements provide constraints on glacier hydraulics. We find that the tremors are generated by subglacial water flow, in moulins, and by icequake bursts. The dominating process can vary on sub-kilometer and sub-daily scales. Consistent with field observations, continuous source tracking via matched-field processing suggests a gradual up-glacier progression of an efficient drainage system as the melt season progresses. The ice-marginal lake likely connects to this drainage system via hydrofracturing, which is indicated by sustained icequake signals emitted from the proximity of the lake basin and starting roughly 24 h prior to the lake drainage. To estimate the hydraulics associated with the drainage, we use tremor–discharge scaling relationships. Our analysis suggests a pressurization of the subglacial environment at the drainage onset, followed by an increase in the hydraulic radii of the conduits and a subsequent decrease in the subglacial water pressure as the capacity of the drainage system increases. The pressurization is in phase with the drop in the lake level, and its retrieved maximum coincides with ice uplift measured via GPS. Our results highlight the use of cryo-seismology for monitoring glacier hydraulics.


Sign in / Sign up

Export Citation Format

Share Document