scholarly journals Experiment On Fluid Regime Under Different Rotate Velocity In Physical Simulation of Titanium Vertical Centrifugal Casting

2021 ◽  
Author(s):  
Yajun Yin ◽  
Xin Peng ◽  
Gen Xiao ◽  
Xiwang Qie ◽  
Xu Shen ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Rotational Speed ◽  
Physical Simulation ◽  
Flow Behavior ◽  
Centrifugal Casting ◽  
Curved Surface ◽  
High Speed Photography ◽  
Filling Process ◽  
Front Edge ◽  
Average Curvature

Abstract In this paper, the physical simulation of filling process of vertical centrifugal casting (VCC) of complex titanium alloy casting was studied. Combined with the mature PTV particle tracking technology, the high-speed photography pictures of the filling process of VCC at different rotational speeds were obtained. The trajectory and velocity information of tracer particles in the rotating flow field were obtained by the corresponding analysis software. Then, through the analysis and modeling of quantitative experimental data, the flow behavior characteristics and movement law of titanium alloy melt in the mold cavity under different mold speeds were studied. The results show that: 1. When the mold is still, the front edge of the filling fluid forms a curved surface with the curvature center pointing to the outside of the mold; when the mold rotates, the front edge of the liquid flow forms a curved surface with the curvature center pointing to the inside of the mold; 2. With the increase of the mold rotation speed, the speed of the fluid filling the mold increases significantly; when the rotational speed is greater than 120 rpm, the fluid still has a certain driving force in the mold center far away from the gate It is good for filling the inner corner of mold with fluid; 3. When the rotational speed of centrifugal casting of titanium alloy reaches 45 rpm or above, typical turbulent vortices appear in the wake; with the increase of rotating speed to 180 rpm, the average curvature radius of turbulent vortices first increases and then decreases, and reaches the minimum value of 0.67 cm at 120 rpm.

scholarly journals Application of the Strain Compensation Model and Processing Maps for Description of Hot Deformation Behavior of Metastable β Titanium Alloy

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2021
Author(s):  
Oleksandr Lypchanskyi ◽  
Tomasz Śleboda ◽  
Aneta Łukaszek-Sołek ◽  
Krystian Zyguła ◽  
Marek Wojtaszek
Keyword(s):  
Titanium Alloy ◽  
Strain Rate ◽  
Flow Behavior ◽  
Microstructural Analysis ◽  
Calculated Data ◽  
Processing Temperature ◽  
Processing Maps ◽  
Compression Tests ◽  
Strain And Strain Rate ◽  
Average Absolute Relative Error

The flow behavior of metastable β titanium alloy was investigated basing on isothermal hot compression tests performed on Gleeble 3800 thermomechanical simulator at near and above β transus temperatures. The flow stress curves were obtained for deformation temperature range of 800–1100 °C and strain rate range of 0.01–100 s−1. The strain compensated constitutive model was developed using the Arrhenius-type equation. The high correlation coefficient (R) as well as low average absolute relative error (AARE) between the experimental and the calculated data confirmed a high accuracy of the developed model. The dynamic material modeling in combination with the Prasad stability criterion made it possible to generate processing maps for the investigated processing temperature, strain and strain rate ranges. The high material flow stability under investigated deformation conditions was revealed. The microstructural analysis provided additional information regarding the flow behavior and predominant deformation mechanism. It was found that dynamic recovery (DRV) was the main mechanism operating during the deformation of the investigated β titanium alloy.

Correlation between Flow Behavior and Microstructure Evolution during α/β Deformation of TA19 Titanium Alloy

2016 ◽  
Vol 18 (10) ◽  
pp. 1808-1815 ◽  
Author(s):  
Ke Wang ◽  
Dongliang Sun ◽  
Yanlin Wu ◽  
Renlong Xin ◽  
Mingyu Wu ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Microstructure Evolution ◽  
Flow Behavior

scholarly journals Research on Cutting Force and Surface Integrity of TC18 Titanium Alloy by Longitudinal Ultrasonic Vibration Assisted Milling

2021 ◽  
Author(s):  
Weibo Xie ◽  
Xikui Wang ◽  
Erbo Liu ◽  
Jian Wang ◽  
Xiaobin Tang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Cutting Force ◽  
Ultrasonic Vibration ◽  
Surface Integrity ◽  
Rotational Speed ◽  
Three Dimensional ◽  
Cutting Temperature ◽  
Surface Residual Stress ◽  
Deformation Layer ◽  
Vibration Milling

Abstract In order to study the influence of rotational speed and amplitude on the surface integrity, TC18 titanium alloy samples were milled by the process of conventional milling and longitudinal ultrasonic vibration assisted milling. The experimental data were obtained by dynamometer, thermometer, scanning electron microscope, X-ray diffractometer and three-dimensional surface topography instrument for observation and analysis. The results show that the rotational speed has a significant effect on the cutting force, cutting temperature, surface morphology and surface residual stress. Compared with ordinary milling, the surface micro-texture produced by ultrasonic vibration milling is more regular, , and with the increase of rotational speed, the influence of ultrasonic vibration on cutting force and cutting temperature decrease. There are adverse effects on surface roughness after ultrasonic vibration superposition. The influence of ultrasonic vibration on the surface residual compressive stress is also greatly reduced when the rotational speed is greater than 2400 rpm. In addition, a certain depth of plastic deformation layer can be formed under the surface of ultrasonic vibration machining, and the depth of deformation layer increases with the increase of vibration.

scholarly journals Investigation of Avalanche Time and Carr’s Index of Poultry Litter Powder as Flowability Indices

2012 ◽  
Vol 45 (4) ◽  
pp. 15-27 ◽  
Author(s):  
I. Valaei ◽  
S.R. Hassan-Beygi ◽  
M.H. Kianmehr ◽  
J. Massah
Keyword(s):  
Particle Size ◽  
Moisture Content ◽  
Rotational Speed ◽  
Flow Behavior ◽  
Poultry Litter ◽  
Primary Source ◽  
Critical Factor ◽  
Bulk Solid ◽  
Tap Density ◽  
Powder Avalanche

Abstract The world’s dependence on chemical fertilizer as the primary source for enriching agricultural fields is continually increasing that cause nature pollution. This has led researchers to aggressively investigate renewable fertilizer resources, biomass, to produce organic crops and reduced wastage. Poultry litter is a bulk solid and biomass feed stocks. Flow behavior of bulk solid is a critical factor in designing and developing suitable equipments (e.g. pelletizing machine). The bulk density, tap density, Carr’s index and powder avalanche time technique were applied to evaluate the flow properties of poultry litter. The experiments were carried out at moisture content (10, 20 and 30% w.b.), particle size (0.3, 0.6 and 1.18 mm) for the bulk and tap densities as well as Carr’s index. In addition to the moisture content (10, 20 and 30 %w.b.) and particle size (0.3, 0.6 and 1.18 mm) the rotational speed of drum (0.5, 1 and1.5 rpm) were also investigated for the avalanche time. The results showed that with increasing moisture content Carr’s index increased significantly (P<0.01) in the ranges of 16.2% to 18.5% and with increasing particle size the Carr’s index decreased from 20.35% to 14.78%. The litter powder avalanche time (AT) increased significantly (P<0.01) with increasing moisture content and decreasing rotational speed and particle size. The bulk and tap densities of the litter powder was decreased with increasing moisture content and increasing the particle size. The bulk and tap densities of the driest and finest poultry litter sample were higher than other ones.

Influence of Circumferential Inflow Distortion on the Performance of a Low Speed, High Aspect Ratio Contra Rotating Axial Fan

2014 ◽  
Vol 136 (7) ◽  
Author(s):  
Chetan Mistry ◽  
A. M. Pradeep
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Rotational Speed ◽  
Total Pressure ◽  
Flow Behavior ◽  
Axial Fan ◽  
Low Speed ◽  
Overall Performance ◽  
Design Speed ◽  
Inflow Conditions

The influence of circumferential inflow distorted on the performance and flow behavior of a high aspect ratio, low speed contra rotating fan is reported in this paper. The total pressure at the inlet is artificially distorted by means of 90 deg mesh sector with a porosity of 0.70. The performance of the contra rotating fan was studied under different speed combinations of the two rotors under clean and distorted inflow conditions. Detailed flow analyses were conducted under design and off-design conditions. In order to understand the effect of distortion and its extent, the distortion sector was rotated circumferentially at intervals of 15 deg to cover the entire annulus. Detailed measurements of the total pressure, velocity components, and flow angles were carried out at the inlet of the first rotor, between the two rotors, and at the exit of the second rotor. The study reveals a few interesting aspects on the effect of inflow distortion on the performance of a contra-rotating stage. For the design speed combination and lower rotational speed of rotor-2, a reduction in the overall operating range with a shift of the peak pressure point towards higher mass flow rate, was observed. It is observed that the effect of inflow distortion at the inlet of rotor-1 gets transferred in the direction of rotor-1 rotation and spreads across the entire annulus. The opposite sense of rotation of rotor-2 causes the distortion effect to get transferred in the direction of rotation of rotor-2 with an associated reduction in the total pressure near the hub. It is observed that a higher rotational speed of the second rotor has a beneficial effect on the overall performance due to the strong suction by generated higher rotational speed of rotor-2.

Heat Transfer Evaluation for a Two-Pass Smooth Wall Channel: Stationary and Rotating Cases

2019 ◽  
Vol 142 (6) ◽  
Author(s):  
Mandana S. Saravani ◽  
Nicholas J. DiPasquale ◽  
Ahmad I. Abbas ◽  
Ryoichi S. Amano
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Rotational Speed ◽  
Numerical Study ◽  
Flow Behavior ◽  
Smooth Wall ◽  
Eddy Simulation ◽  
Large Eddy ◽  
The Heat Transfer Coefficient ◽  
Good Agreement

Abstract This study presents findings on combined effects of Reynolds number and rotational effect for a two-pass channel with a 180-deg turn, numerically and experimentally. To have a better understanding of the flow behavior and to create a baseline for future studies, a smooth wall channel with the square cross section is used in this study. The Reynolds number varies between 6000 and 35,000. Furthermore, by changing the rotational speed, the maximum rotation number of 1.5 is achieved. For the numerical investigation, large eddy simulation (LES) is utilized. Results from the numerical study show a good agreement with the experimental data. From the results, it can be concluded that increasing both Reynolds number and rotational speed is in favor of the heat transfer coefficient enhancement, especially in the turn region.

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