Experimental Investigation and Modelling of the Angular Velocity as a Function of the Radius in Molten Ga75In25 Alloy and Mercury Stirred by Rotation Magnetic Field | Chapter 3 | Current Research Progress in Physical Science Vol. 9

The simulation of the solidification of alloys (like the steels or aluminium alloys) which calculates the melt flow induced by RMF, needs a correct angular velocity vs radius function of the melt. Because it is impossible to obtain information about the melt flow from industrial casting directly, this information can only be obtained from well-monitored experiments using low melting point metals or alloys (e.g., Hg, Ga, GaIn). In this work, the measuring methods suitable for determining this function and analysed for their advantages and disadvantages were first summarised. The angular velocity as a function of the radius was measured by two different methods.

The first one is the Pressure Compensation Method (PCM). In this case, closed TEFLON crucibles with 60 mm length and 12.5 mm radius and Ga75wt%In25wt% alloy were used. The angular velocity (ω) was calculated from the compensation pressure measured at r = 5, 7.5, 10, and 12.5 mm in the 0 – 90 mT range of magnetic induction.

In the case of the second one, a series of data from the literature was processed. The experiments were carried out with the Turbine Wheel Method (TWM), Hg flowing in a glass tube with a diameter of 60 mm, which can be considered practically infinitely long. The value of ω was determined as a function of the radius by an anemometer immersed in Hg. The maximum value of B was 25 mT. A Two-poles inductor with 50 Hz was used in both cases.

After processing the data, it was found that (i) the angular velocity varies significantly along the radius, growing from the wall to the centre of the crucible, contrary to the assumption often used in simulations that it is constant and (ii) at the wall of the crucible, the angular velocity is not zero, contrary to the generally accepted fact that it is definitely zero.

A physical model and two types of mathematical descriptions were developed based on the two ω (B, r) datasets. The two types of ω (B, r) functions could be suitable for the validation of the simulation of melt flow during the solidification of alloys produced by RMF.

 

Author (s) Details

Andras Roosz
Institute of Physical Metallurgy, Metalforming and Nanotechnology, University of Miskolc, 3515 Miskolc, Hungary and HUN-REN-ME Materials Science Research Group, 3515 Miskolc, Hungary.

 

Arnold Ronafoldi
Institute of Physical Metallurgy, Metalforming and Nanotechnology, University of Miskolc, 3515 Miskolc, Hungary and HUN-REN-ME Materials Science Research Group, 3515 Miskolc, Hungary.

 

Maria Sveda
Institute of Physical Metallurgy, Metalforming and Nanotechnology, University of Miskolc, 3515 Miskolc, Hungary and HUN-REN-ME Materials Science Research Group, 3515 Miskolc, Hungary.

 

Zsolt Veres
Institute of Physical Metallurgy, Metalforming and Nanotechnology, University of Miskolc, 3515 Miskolc, Hungary and HUN-REN-ME Materials Science Research Group, 3515 Miskolc, Hungary.

 

Please see the book here:- https://doi.org/10.9734/bpi/crpps/v9/4705

Energy Loss at the Base of a Free Straight Drop Spillway | Chapter 2 | Current Overview on Science and Technology Research Vol. 6

 Vertical drop or free overflow is a common feature of both natural and man-made canals. Natural drips are formed by bed erosion, while artificial drips are incorporated into irrigation systems to reduce canal slopes to design slopes. A gradual overflow results in greater energy loss. Greater energy dissipation is caused by the jet mixing with the pool at the downstream end of each droplet. As a result, this accounts for the reduced energy dissipation commonly present in drop chips and gradual overflows. In this work, we investigate the energy dissipation of linear droplets through the creation of a physical model. Effective geometric and hydraulic parameters were determined and three drops of different heights were made from plexiglass. These physics models were installed in his two existing channels at the Hydropower Laboratory at Tabriz University, Iran. Several runs of the physical model were performed to determine the key parameters for determining energy dissipation. The results show that droplet energy dissipation is affected by droplet height and ejection. The predicted relative energy dissipation varied from 10.0% (for yc/h = 0.94) to 94.3% (for yc/h = 0.02). Energy loss due to falling is primarily due to mixing of the jet with the pool behind the jet, which entraps air bubbles in the flow. A statistical model was developed to predict the energy dissipation of droplets that exhibits nonlinear correlations between effective parameters. Comparing this work with the results of his Moore, Rand, White, Rajaratnam and Chamani, White's model overestimates the droplet energy dissipation and Rand's model underestimates the droplet energy dissipation. I understand. Others can predict energy dissipation similarly to the proposed statistical model. The length of the downstream calm basin predicted by White is 20% shorter than the others.

Author(s) Details:

Farzin Salmasi,
Department of Water Engineering, Faculty of Agriculture, University of Tabriz, Tabriz, Iran.

John Abraham,
University of St. Thomas, Minnesota, School of Engineering 2115 Summit Avenue St. Paul, Minnesota 55105, USA.

Please see the link here: https://stm.bookpi.org/COSTR-V6/article/view/8412

On the Method of Reducing the Magnitude of an Impending Catastrophic Earthquake | Chapter 1 | Challenging Issues on Environment and Earth Science Vol. 1

The ideas devoted to the project of developing new sensors and new vibrators are created in this chapter and are important for the project to reduce the magnitude of an imminent catastrophic earthquake. A physical and mathematical model of a mercury earthquake precursor sensor prototype is suggested, and the signal obtained by the old sensor is measured. Examination of a current version of a sensor provides an understanding of physical processes and reveals the fundamental value of the new sensor. Tens of hours before the earthquake, which is needed for the project to minimise the severity of an imminent catastrophic earthquake, this sensor helps to determine the epicentre of a potential short-focus earthquake. To define the physical mechanism for reducing the severity of an imminent catastrophic earthquake, an approach is formulated. The need for new vibrators is formulated with a view to reducing the severity of an imminent catastrophic earthquake. The chapter details a vibrator patent that is based on a new physical theory.

Author (s) Details

M. G. Noppe
Department of Applied and Theoretical Physics, NSTU, Israel (Retired).

View Book :- https://stm.bookpi.org/CIEES-V1/issue/view/33