Implant Fixture Heat Transfer During Abutment Preparation

The purpose of the study was to evaluate the effect of water flow rate on the heat transmission in implants during abutment preparation using a diamond bur in a high-speed dental turbine. Titanium-alloy abutments (n = 32) were connected to a titanium-alloy implant embedded in an acrylic resin within a water bath at a controlled temperature of 37°C. The specimens were equally distributed into 2 groups (16 each) according to the water flow rate used during the preparation phase. Group 1 had a water flow rate of 24 mL/min, and group 2 had a water flow rate of 40 mL/min. Each abutment was prepared in the axial plane for 1 minute and in the occlusal plane for 1 minute with a coarse tapered diamond bur using a high-speed dental handpiece. Thermocouples embedded at the cervix of the implant surface were used to record the temperature of heat transmission from the abutment preparation. Heat generation was measured at 3 distinct times (immediately and 30 seconds and 60 seconds after the end of preparation). Statistical analyses were carried out using 2-way analysis of variance and the Student t test. Water flow rates (24 mL vs 40 mL) and time interval had no statistically significant effect on the implant's temperature change during the abutment preparation stage (P = .431 and P = .064, respectively). Increasing the water flow rate from 24 to 40 mL/min had no influence on the temperature of the implant fixture recorded during preparation of the abutment.

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Experimental Characterization of a Modified Airlift Pump

Volume 7: Fluids Engineering Systems and Technologies ◽

10.1115/imece2014-39899 ◽

2014 ◽

Author(s):

Afshin Goharzadeh ◽

Keegan Fernandes

Keyword(s):

Water Flow ◽

Flow Rate ◽

High Speed ◽

Water Flow Rate ◽

High Speed Photography ◽

Two Phase ◽

Inner Diameter ◽

Airlift Pump ◽

Flow Map ◽

Churn Flow

This paper presents an experimental investigation on a modified airlift pump. Experiments were undertaken as a function of air-water flow rate for two submergence ratios (ε=0.58 and 0.74), and two different riser geometries (i) straight pipe with a constant inner diameter of 19 mm and (ii) enlarged pipe with a sudden expanded diameter of 19 to 32 mm. These transparent vertical pipes, of 1 m length, were submerged in a transparent rectangular tank (0.45×0.45×1.1 m3). The compressed air was injected into the vertical pipe to lift the water from the reservoir. The flow map regime is established for both configurations and compared with previous studies. The two phase air-water flow structure at the expansion region is experimentally characterized. Pipeline geometry is found to have a significant influence on the output water flow rate. Using high speed photography and electrical conductivity probes, new flow regimes, such as “slug to churn” and “annular to churn” flow, are observed and their influence on the output water flow rate and efficiency are discussed. These experimental results provide fundamental insights into the physics of modified airlift pump.

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Effect of the Spray Pattern, Water Flow Rate, and Cutting Position on the Cutting Efficiency of High-Speed Dental Handpieces

The International Journal of Prosthodontics ◽

10.11607/ijp.3008 ◽

2013 ◽

Vol 26 (1) ◽

pp. 85-87 ◽

Cited By ~ 3

Author(s):

Wen-jie Yang ◽

Jian Sun

Keyword(s):

Water Flow ◽

Flow Rate ◽

High Speed ◽

Water Flow Rate ◽

Cutting Efficiency ◽

Spray Pattern

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Visualization of Oil Droplets Within ESP Impellers

Volume 8: Polar and Arctic Sciences and Technology; Petroleum Technology ◽

10.1115/omae2017-62424 ◽

2017 ◽

Cited By ~ 1

Author(s):

Rodolfo Marcilli Perissinotto ◽

William Monte Verde ◽

Jorge Luiz Biazussi ◽

Marcelo Souza de Castro ◽

Antonio Carlos Bannwart

Keyword(s):

Water Flow ◽

Flow Rate ◽

High Speed ◽

Average Velocity ◽

Rotation Speed ◽

Water Flow Rate ◽

Oil Droplets ◽

Drag Forces ◽

Electrical Submersible Pump ◽

Velocity Changes

The objective of this research is to investigate the path of oil drops within an Electrical Submersible Pump (ESP) impeller, to evaluate its size and velocity as function of water flow rate and the ESP rotation speed. An experimental study was conducted at University of Campinas - Brazil with an ESP prototype designed to allow flow visualization within the impeller through a transparent shell. A high-speed camera with lighting set captures images of the oil droplets at a rate of 1000 frames per second. The set of data was performed at three rotational speeds — 600 rpm, 900 rpm and 1200 rpm — for three water flow rates — 80%, 100% and 120% of the best efficiency point (BEP). The results reveal that the oil drops become smaller when the rotational speed increases. The same behavior is noticed when the water flow rate increases. Generally, the oil droplets have spherical and elliptical shapes that change as function of their position inside the impeller channel. Furthermore, the drops have random trajectories, but a pattern can be detected in three cases: droplets near the pressure blade, droplets near the suction blade and droplets that move from the suction blade to the pressure blade. The average velocity of the oil droplets that move near the suction blade is significantly higher than the average velocity of the droplets that move near the pressure blade. Velocity changes as function of the impeller radius suggest different accelerations that may be caused by drag forces and pressure forces. The size of the oil drops has no significant influence on their velocities.

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Spray Generated by an Airblast Atomizer at High-Pressure Conditions

Volume 2: Turbo Expo 2007 ◽

10.1115/gt2007-27803 ◽

2007 ◽

Cited By ~ 9

Author(s):

Feras Z. Batarseh ◽

Ilia V. Roisman ◽

Cam Tropea

Keyword(s):

Water Flow ◽

Flow Rate ◽

High Speed ◽

Velocity Vector ◽

Ambient Pressure ◽

Air Flow ◽

Water Flow Rate ◽

The Other ◽

Air Flow Rate ◽

Spray Visualization

We present an experimental investigation of a spray generated by an airblast atomizer. Experiments have been performed in a pressure chamber equipped by transparent windows allowing an optical access to the spray. Several techniques of spray investigation have been applied: spray visualization using the high-speed video system, spray visualization and instantaneous velocity measurements using the PIV technique, spray velocimetry and sizing using the IPI and phase Doppler instruments. Phase Doppler instrument has been used to characterize the droplets in the spray: their diameter, two components of the velocity vector. Also the integral parameters of the spray, such as the local volume flux density, have been characterized. We conduct a parametric study of the effect of the ambient pressure, the air flow rate and the water flow rate on an atomized spray. Measurements at different radial locations in the spray and in two planes were performed. The measurements in these two planes allow one to determine the distributions of all the three components of the average drop velocity vector: axial, radial and azimuthal. PDA measurements show that atomized spray is sensitive to any change in the studied parameters. For example, increasing air flow rate from 20 SCMH to 45 SCMH and keeping same water flow rate and pressure, leads to an increase in all velocity components and also to a change in droplets diameters. On the other hand, keeping constant pressure and air flow rate and increasing water flow rate from 0.7 to 1.4 l/hr, leads to an increase in water droplets sizes and the axial velocity component, whereas the other velocity components show a non uniform change. Moreover, increasing the ambient pressure leads to the growth of the spray velocity and drops diameters.

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Effect of Water Flow on Underwater Wet Welded A36 Steel

Metals ◽

10.3390/met11050682 ◽

2021 ◽

Vol 11 (5) ◽

pp. 682

Author(s):

Eko Surojo ◽

Aziz Harya Gumilang ◽

Triyono Triyono ◽

Aditya Rio Prabowo ◽

Eko Prasetya Budiana ◽

...

Keyword(s):

Mechanical Properties ◽

Water Flow ◽

Flow Rate ◽

Water Flow Rate ◽

Physical And Mechanical Properties ◽

Shielded Metal Arc Welding ◽

Effect Of Water ◽

Bending Effect ◽

Metal Arc Welding ◽

A36 Steel

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.

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Design and thermal characteristic analysis of motorized spindle cooling system

Advances in Mechanical Engineering ◽

10.1177/16878140211020878 ◽

2021 ◽

Vol 13 (5) ◽

pp. 168781402110208

Author(s):

Yuan Zhang ◽

Lifeng Wang ◽

Yaodong Zhang ◽

Yongde Zhang

Keyword(s):

Flow Rate ◽

High Speed ◽

Thermal Deformation ◽

Cooling System ◽

Thermal Characteristic ◽

Water Flow Rate ◽

Thermal Characteristics ◽

Characteristic Analysis ◽

Motorized Spindle ◽

Experiment And Simulation

The thermal deformation of high-speed motorized spindle will affect its reliability, so fully considering its thermal characteristics is the premise of optimal design. In order to study the thermal characteristics of high-speed motorized spindles, a coupled model of thermal-flow-structure was established. Through experiment and simulation, the thermal characteristics of spiral cooling motorized spindle are studied, and the U-shaped cooled motorized spindle is designed and optimized. The simulation results show that when the diameter of the cooling channel is 7 mm, the temperature of the spiral cooling system is lower than that of the U-shaped cooling system, but the radial thermal deformation is greater than that of the U-shaped cooling system. As the increase of the channel diameter of U-shaped cooling system, the temperature and radial thermal deformation decrease. When the diameter is 10 mm, the temperature and radial thermal deformation are lower than the spiral cooling system. And as the flow rate increases, the temperature and radial thermal deformation gradually decrease, which provides a basis for a reasonable choice of water flow rate. The maximum error between experiment and simulation is 2°C, and the error is small, which verifies the accuracy and lays the foundation for future research.

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