Numerical Modeling of Venturi Flume

In order to measure flow rate in open channels, including irrigation channels, hydraulic structures are used with a relatively high degree of reliance. Venturi flumes are among the most common and efficient type, and they can measure discharge using only the water level at a specific point within the converging section and an empirical discharge relationship. There have been a limited number of attempts to simulate a venturi flume using computational fluid dynamics (CFD) tools to improve the accuracy of the readings and empirical formula. In this study, simulations on different flumes were carried out using a total of seven different models, including the standard k–ε, RNG k–ε, realizable k–ε, k–ω, and k–ω SST models. Furthermore, large-eddy simulation (LES) and detached eddy simulation (DES) were performed. Comparison of the simulated results with physical test data shows that among the turbulence models, the k–ε model provides the most accurate results, followed by the dynamic k LES model when compared to the physical experimental data. The overall margin of error was around 2–3%, meaning that the simulation model can be reliably used to estimate the discharge in the channel. In different cross-sections within the flume, the k–ε model provides the lowest percentage of error, i.e., 1.93%. This shows that the water surface data are well calculated by the model, as the water surface profiles also follow the same vertical curvilinear path as the experimental data.

Development of Forced Convection Heat Transfer Enhancement System by using Mesh Inserts in a Circular Tube

In the present work, aluminium mesh type inserts flow has been developed. The aluminium meshes are arranged on spokes at the angle of 00, 450, 900 concerning horizontal are inserted in the test section to create turbulence. To carry out an experimental investigation using this mesh inserts, we have developed a forced convection system. In this system, we have wounded three 200 Volt heaters over a 500 mm test section of 25 mm diameter respectively. The input to the heater is controlled by a variable dimmer stat, and the mass flow rate is controlled by an orifice meter with a diameter of 25 mm across which the manometer is connected to measure flow rate. Experiments were carried out at Reynolds number greater than 4000. The experimental setup was validated first and readings with different inserts were taken. This led to the conclusion that the rate of heat transfer was improved by using mesh inserts inclined at an angle 00, 450, and 900. Among these, the inserts inclined at 450 angles showed maximum heat transfer rate i.e., 37.44%, 29.95%, and 38.40% for the manometric reading of 5 mm, 4 mm, and 3 mm respectively.

Identification of Characteristic Parameters for Hydrostatic Bearings

ABSTRACTThis study proposes a method to identify the characteristic parameters of hydrostatic bearing. When load or supply pressure changed, the inlet and outlet pressures of restrictor, flow rate and worktable displacement are examined for establish identification equations. The practical values of the characteristic parameters can be obtained by minimizing the differences between measure flow rate and identify flow rate. The differences between practical and design values of these parameters can be used to calibrate design parameters for satisfying the requirements.

Experimental Study of Various Porosity of Fractal Flow Conditioner for Orifice Plate Flowmeters

The plant industry is required to measure flow rate more accurately to meet plant operation and cost accounting objectives. The opposing concern of improving flow meter accuracy is resolved by using flow conditioners. The distance of implementation of flow conditioner upstream of the orifice plate flowmeter is also need to be addressed. Hence, in present study, an analysis of the porosity of fractal flow conditioner towards orifice plate flowmeter’s accuracy and the best distance of fractal flow conditioner upstream of the orifice plate flowmeter was determined. In an experimental work, a different porosity of the fractal flow conditioners were installed with different distance upstream of the orifice plate in conjunction with the different disturbances to assess the effects of these devices on the measurement of the mass flow rate. Data gained for all the plates showed that there is increment of pressure drop and change in discharge coefficient of the orifice with lower β value of fractal flow conditioner. Good comparisons with the previous experimental work demonstrate the fractal flow conditioner can preserve the accuracy of metering up to the level required in the standards.

Oil and Grease Removal from Industrial Wastewater Using New Utility Approach

The present study is an attempt to investigate oil and grease pollution that may pollute fresh water and influence aquatic environment. Then removal of oil and grease from manufacturing wastewater befall essential but common techniques not enough. Enzyme and adsorption units representing major developed new laboratory were selected to assess the water quality and humiliation prospective of oil and grease from wastewater. Several components and environmental variables that were dissolved oxygen, bacteriology measure, flow rate and adsorption material amount studied to assess the removal performance of oil and grease. The results elucidated significant variations among different tests which influenced microbial necessary role of oxidation declining develop biological treatment process reached to 72%. The study stressed out natural material (zeolite) that enhanced organic reduction under optimal conditions. These conditions were closer spacing and high length of adsorbing unit that led to increase oil and grease contact period with adsorbent and added to increase performance removal reached to 99%.

Research on the Field Test Methods of Flow Rate and Water Level of Urban Drainage Pumping Stations

The flow rate and water level measure is one key work of the pumping station field test. And the reliable, applicable, economic and effective measurement method and instruments are the key decisive factors of the field test. The urban drainage pumping stations usually pump sewage, and its inlet structure and outlet structure generally use closed arrangement. These make the flow rate and water level measurement of the field test become complicated. Based on the characteristics of urban drainage pumping station, this paper analyzed the measurement methods of flow rate and water level parameters of the field test for urban drainage pumping station. In combination with a field test case for an urban drainage pumping station, this paper demonstrated how to choose the reliable, applicable, economic and effective measurement method to measure flow rate and water level parameters.

Uncertainty Analysis in Fan Testing

The ASME performance test codes require an uncertainty analysis as part of a code test, and some codes require both a pre-test and a post-test uncertainty analysis. ASME PTC-19.1, Test Uncertainty provides the basic approach to conducting an uncertainty analysis. The individual test codes, such as ASME PTC-11, Fans, provide specific guidance for uncertainty analysis of tests of particular equipment or processes. The following issues related to an uncertainty analysis for a PTC-11 fan test are discussed. • Evaluating uncertainties for traverse measurements — Fan testing requires one or more traverses to measure flow rate as well as various pressures, temperatures, and gas composition. Evaluating and propagating the uncertainty associated with traverse point measurements to obtain overall uncertainty is explained. • Evaluating uncertainties for non-traverse measurements — Fan testing also requires the measurement of power input, fan speed, and atmospheric temperature and pressure. Evaluating the uncertainties in these quantities is discussed. • Propagating uncertainties of the measurements into the final results — An analytical method is compared to “dithering” to obtain a sensitivity factor. • Using a pre-test uncertainty analysis to optimize the test design — Examples are provided on how a pre-test uncertainty analysis can be used to reduce the uncertainties of a fan test. The results include results of sample pre-test and post-test uncertainty analyses for fans.