Experimental Analysis of a Particle Separator Design With Full-Field Three-Dimensional Measurements

2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Daniel D. Borup ◽  
Christopher J. Elkins ◽  
John K. Eaton
Keyword(s):  
Volume Fraction ◽  
Swirling Flow ◽  
Dominant Role ◽  
Particle Volume Fraction ◽  
Dust Particles ◽  
Working Fluid ◽  
Internal Cooling ◽  
Full Field ◽  
Cooling Passage ◽  
Particle Separator

Abstract Particle ingestion into turbine engines can cause significant damage through deposition in internal cooling passages. Musgrove et al. proposed a compact particle separator installed between the combustor bypass exit and turbine vane cooling passage inlet. The design had small pressure losses but provided limited particle separation. Its performance has proved difficult to replicate. Borup et al. recently developed a magnetic resonance imaging (MRI)-based technique for full-field, 3D measurements of the mean particle concentration distribution in complex flows. A particle separator based on the Musgrove et al. design was fabricated out of plastic using 3D printing, with the addition of a drain from the collector through which 3% of the total flow was extracted. The separator efficiency was measured at two Reynolds numbers, using water as the working fluid and 33-μm titanium microspheres to represent dust particles. Stokes number was shown to play the dominant role in determining efficiency across studies. MRI was used to obtain the 3D particle volume fraction and three-component velocity fields. The velocity data showed that flow was poorly distributed between the separator louvers, while the collector flow followed the optimal pattern for particle retention. The MRI data revealed that strong swirling flow in the collector centrifuged particles toward the outer wall of the collector and into a partitioned region of quiescent flow, where they proceeded to exit the collector. Future designs could be improved by re-arranging the louvers to produce a more uniform flow distribution, while maintaining the effective collector design.

Experimental Analysis of a Particle Separator Design With Full-Field 3D Measurements

2019 ◽  
Author(s):  
Daniel D. Borup ◽  
Christopher J. Elkins ◽  
John K. Eaton
Keyword(s):  
Volume Fraction ◽  
Dominant Role ◽  
Particle Volume Fraction ◽  
Dust Particles ◽  
Working Fluid ◽  
Distribution Data ◽  
Full Field ◽  
3D Measurements ◽  
Cooling Passage ◽  
Particle Separator

Abstract Particle ingestion into turbine engines is a widespread problem that can cause significant degradation in engine service life. One primary damage mechanism is deposition of particulate matter in internal cooling passages. Musgrove et al. proposed a compact particle separator that could be installed between the combustor bypass exit and turbine vane cooling passage inlet. The design had small pressure losses but provided limited particle separation, and its performance has proved difficult to replicate in subsequent experiments. Borup et al. recently developed a Magnetic Resonance Imaging (MRI) based technique for making full-field, 3D measurements of the mean particle concentration distribution in complex flows. A particle separator based on the Musgrove et al. design was fabricated out of plastic using 3D printing. The primary difference from earlier designs was the addition of a drain from the collector, through which 3% of the total flow was extracted. The separator efficiency was measured at two Reynolds numbers, using water as the working fluid and 33-micron titanium microspheres to represent dust particles. Particle Stokes number was shown to play the dominant role in determining efficiency across studies. MRI was used to obtain the 3D particle volume fraction and 3-component velocity fields. The velocity data showed that flow was poorly distributed between the separator louvers, while the collector flow followed the optimal pattern for particle retention. The particle distribution data revealed that strong swirling flow in the collector centrifuged particles towards the outer wall of the collector and into a partitioned region of quiescent flow, where they proceeded to exit the collector via the drain. Future designs could be improved by re-arranging the louvers to produce a more uniform flow distribution, while maintaining the effective collector design.

Microstructure and mechanical properties of AlCrFeCoNi high-entropy alloy particle reinforced Mg-9Al-1Zn matrix composites

2021 ◽  
Vol 112 (7) ◽  
pp. 538-545
Author(s):  
Yongsheng Chen ◽  
Zesheng Ji ◽  
Maoliang Hu ◽  
Hongyu Xu ◽  
Guangjie Feng
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Volume Fraction ◽  
Dominant Role ◽  
Particle Volume Fraction ◽  
Stress Transfer ◽  
High Entropy Alloy ◽  
Compression Tests ◽  
Particle Volume ◽  
High Entropy

Abstract AlCrFeCoNi particles were added to Mg-9Al-1Zn alloy in a rotary blowing process. The microstructures and mechanical properties of Mg-9Al-1Zn based composites were characterized by means of X-ray diffraction, optical microscopy, scanning electron microscopy, transmission electron microscopy, and tensile and compression tests at room temperature. Results revealed that AlCrFeCoNi particles could effectively refine the grains, and the rotary blowing process enabled the uniform distribution of these particles. The mechanical properties of composites improved with the increase of particle volume fraction. The superior wettability of AlCrFeCoNi particles supported their reliable bonding with the Mg-9Al-1Zn matrix. The Hall–Petch strengthening and stress transfer effect played a dominant role in the improvement of compressive and tensile properties.

Heat Sink Performance Improvement by Way of Nanofluids

2016 ◽  
Author(s):  
J. L. Zúñiga-Cerroblanco ◽  
C. Ulises Gonzalez-Valle ◽  
Daniel Lorenzini-Gutierrez ◽  
Abel Hernandez-Guerrero ◽  
Jaime Cervantes de Gortari
Keyword(s):  
Integrated Circuit ◽  
Heat Sink ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Working Fluid ◽  
Field Pattern ◽  
Air Cooling ◽  
Base Temperature ◽  
Material Base ◽  
Particle Volume

The new generation of integrated-circuit chips demands novel cooling techniques for enhancing device performance. Air-cooling techniques are not sufficient anymore to reach the necessary dissipation for these devices while liquid-cooling techniques have proved to be an efficient solution. The addition of nanoparticles to conventional cooling fluid changes its thermo-physical properties based on the type of the particle material, base fluid, particle volume fraction and size, pumping power, etc. The present study proposes a flow field pattern for a nanofluid-cooled heat sink in order to improve the heat transfer and the flow distribution based on a new design. Al2O3 - water nanofluid is the working fluid. The results show the comparison between the simple conventional use of water and the use of a nanofluid, by way of implementing critical factors for performance evaluation: thermal resistance, temperature uniformity, highest base temperature, and pressure drop. The analysis enables to determine that the heat sink thermal performance is definitely improved by the use of a nanofluid.

Applications of Advanced Liquid Crystal Video Thermography to Turbine Cooling Passage Heat Transfer Measurement

1996 ◽  
Author(s):  
Robert P. Campbell ◽  
Michael J. Molezzi
Keyword(s):  
Heat Transfer ◽  
Liquid Crystal ◽  
Gas Turbine ◽  
Leading Edge ◽  
Internal Cooling ◽  
Thermochromic Liquid Crystal ◽  
Transfer Coefficients ◽  
Full Field ◽  
Multiple Data Sets ◽  
Cooling Passage

Over the past few years advances in thermochromic liquid crystal (TLC) thermography have improved its usefulness as a quantitative temperature measurement technique. Many of these improvements have been discussed in the literature but few have been directly applied to solving gas turbine heat transfer problems. The purpose of this work is to combine the best of these techniques into an advanced, easy to use, low cost system which can provide accurate, rapid and complete heat transfer data for advanced gas turbine development. The older, more common technique of using narrow band liquid crystals to map isotherm distributions has been updated to use wide temperature range crystals with full hue-temperature calibrations over their entire response range with accuracy as good or better than thermocouples. The system consists of an RGB video camera, a hue, saturation and intensity (HS1) framegrabber, on-axis lighting and a linear thermal gradient TLC calibrator. Algorithms have been developed for automated data validation, spatial transformations of data taken on non-planar surfaces and superposition of multiple data sets to construct full field data over surfaces with wide ranges of heat transfer coefficients (h). Instead of yielding mean h, h at a few thermocouple locations or h at individual isotherms, this system provides continuous distributions of h. These techniques have been used to map the heat transfer coefficient distributions in advanced power generation gas turbine internal cooling passages. These include serpentine passages with and without turbulators, leading edge passages and 180° rums. Results are presented in full field plots of heat transfer enhancement, Nu(x,y)/Nudb.

Heat transfer comparison investigation of mist/steam two-phase flow and steam in a square smooth channel

2019 ◽  
Vol 233 (7) ◽  
pp. 877-889
Author(s):  
Xiaojun Shi ◽  
Guangwen Jiang ◽  
Jianmin Gao ◽  
Guanwen Chen ◽  
Liang Xu
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Gas Turbine ◽  
Wall Temperature ◽  
Two Phase Flow ◽  
Working Fluid ◽  
Internal Cooling ◽  
Phase Flow ◽  
Two Phase ◽  
Cooling Passage

A small amount of fine water droplets is injected into steam to form mist/steam two-phase flow as the working fluid of internal cooling passages of blades and vanes, which is a promising cooling technology to replace compressed air cooling for next generation gas turbine. To simulate mist/steam flow in the internal cooling passage of gas turbine blade/vane, a smooth square channel was made by welding four stainless steel plates. The test channel employs a hydraulic diameter of 40 mm and a length of 420 mm. The thickness of the channel plate is 3 mm. The wall temperature distribution and averaged Nusselt number ratio of mist/steam and steam-only in this channel were numerically and experimentally investigated under the same test conditions for comparison. The effects of Reynolds number, wall heat flux and mass flow rate on the heat transfer performance have been analyzed. The results show that within the scope of allowable error the calculated results were acceptable to simulate the experiment subject with the numerical model in this work. Compared with steam-only, the variation trend of wall temperature distribution cooled by the mist/steam is different at the middle region of the test section. The heat transfer coefficient of mist/steam two-phase flow is significantly improved.

scholarly journals Performance improvement of double-tube gas cooler in CO2 refrigeration system using nanofluids

2015 ◽  
Vol 19 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Jahar Sarkar
Keyword(s):  
Performance Improvement ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Cooling Capacity ◽  
Inlet Temperature ◽  
Refrigeration Cycle ◽  
Particle Volume ◽  
Transcritical Carbon Dioxide ◽  
The Given ◽  
Theoretical Analyses

The theoretical analyses of the double-tube gas cooler in transcritical carbon dioxide refrigeration cycle have been performed to study the performance improvement of gas cooler as well as CO2 cycle using Al2O3, TiO2, CuO and Cu nanofluids as coolants. Effects of various operating parameters (nanofluid inlet temperature and mass flow rate, CO2 pressure and particle volume fraction) are studied as well. Use of nanofluid as coolant in double-tube gas cooler of CO2 cycle improves the gas cooler effectiveness, cooling capacity and COP without penalty of pumping power. The CO2 cycle yields best performance using Al2O3-H2O as a coolant in double-tube gas cooler followed by TiO2-H2O, CuO-H2O and Cu-H2O. The maximum cooling COP improvement of transcritical CO2 cycle for Al2O3-H2O is 25.4%, whereas that for TiO2-H2O is 23.8%, for CuO-H2O is 20.2% and for Cu-H2O is 16.2% for the given ranges of study. Study shows that the nanofluid may effectively use as coolant in double-tube gas cooler to improve the performance of transcritical CO2 refrigeration cycle.

A simulation and experimental study on particle volume fraction of PMMA suspension in centrifugal fields

2021 ◽  
Author(s):  
Yosephus Ardean Kurnianto Prayitno ◽  
Tong Zhao ◽  
Yoshiyuki Iso ◽  
Masahiro Takei
Keyword(s):  
Experimental Study ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Particle Volume

Solidification Processing of Functionally Graded Materials by Sedimentation

1999 ◽  
Author(s):  
J. W. Gao ◽  
S. J. White ◽  
C. Y. Wang
Keyword(s):  
Functionally Graded Materials ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Computer Code ◽  
Functionally Graded ◽  
Particle Volume ◽  
Particle Sedimentation ◽  
Graded Materials ◽  
Free Zone ◽  
Free Region

Abstract A combined experimental and numerical investigation of the solidification process during gravity casting of functionally graded materials (FGMs) is conducted. Focus is placed on the interplay between the freezing front propagation and particle sedimentation. Experiments were performed in a rectangular ingot using pure substances as the matrix and glass beads as the particle phase. The time evolutions of local particle volume fractions were measured by bifurcated fiber optical probes working in the reflection mode. The effects of various processing parameters were explored. It is found that there exists a particle-free zone in the top portion of the solidified ingot, followed by a graded particle distribution region towards the bottom. Higher superheat results in slower solidification and hence a thicker particle-free zone and a higher particle concentration near the bottom. The higher initial particle volume fraction leads to a thinner particle-free region. Lower cooling temperatures suppress particle settling. A one-dimensional solidification model was also developed, and the model equations were solved numerically using a fixed-grid, finite-volume method. The model was then validated against the experimental results, and the validated computer code was used as a tool for efficient computational prototyping of an Al/SiC FGM.

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