Recent Advances in Volumetric Flow Measurements: High-Density Particle Tracking (‘Shake-The-Box’) with Navier-Stokes Regularized Interpolation (‘FlowFit’)

2017 ◽  
pp. 587-597
Author(s):  
Daniel Schanz ◽  
Andreas Schröder ◽  
Sebastian Gesemann ◽  
Florian Huhn ◽  
Matteo Novara ◽  
...  
Keyword(s):  
Particle Tracking ◽  
High Density ◽  
Navier Stokes ◽  
Flow Measurements ◽  
Recent Advances

scholarly journals Effect of in-service burnout effect on the transonic leakage flows over cavity tip model

2021 ◽  
pp. 095765092110121
Author(s):  
Zainab J Saleh ◽  
Eldad J Avital ◽  
Theodosios Korakianitis
Keyword(s):  
Turbine Blades ◽  
High Heat ◽  
Navier Stokes ◽  
Gas Temperature ◽  
Flow Measurements ◽  
Tip Leakage ◽  
Leakage Flows ◽  
Operational Life ◽  
Flow Interactions ◽  
Blade Tip

Increasing the gas temperature at the inlet to the high pressure turbine of gas turbine engines is known as a proven method to increase the efficiency of these engines. However, this will expose the blades’ surface to very high heat load and thermal damages. In the case of the un-shrouded turbine blades, the blade tip will be exposed to a significant thermal load due to the developed leakage flows in the tip gap, this leads to in-service burnout which degrades the blade tip and shortens its operational life. This paper studies the in-service burnout effect of the transonic tip flows over a cavity tip which is a configuration commonly used to reduce the tip leakage flows. This investigation is carried out experimentally within a transonic wind tunnel and computationally using steady and unsteady Reynolds Averaged Navier Stokes approaches. Various flow measurements are established and different flow behaviour including separation bubbles, shockwave development and distinct flow interactions are captured and discussed. It is found that when the tip is exposed to the in-service burnout, leakage flow behaves in a significantly different way. In addition, the effective tip gap becomes much larger and allows higher leakage mass flow rate in comparison to the sharp-edge tip (i.e. a tip at the beginning of its operational life). The tip leakage losses are found much higher for the round-edge cavity tip (i.e. a tip exposed to burn-out effect). Experimental and computational flow visualisations, surface pressure measurements and discharge coefficient variation are given and analysed for several pressure ratios across the tip gap.

Recent advances in physiological lipoprotein metabolism

2014 ◽  
Vol 52 (12) ◽  
Author(s):  
Indra Ramasamy
Keyword(s):  
High Density Lipoprotein ◽  
Cholesteryl Ester ◽  
Ldl Receptor ◽  
Lipoprotein Metabolism ◽  
Density Lipoprotein ◽  
High Density ◽  
Low Density ◽  
Transfer Protein ◽  
Recent Advances ◽  
The Right

AbstractResearch into lipoprotein metabolism has developed because understanding lipoprotein metabolism has important clinical indications. Lipoproteins are risk factors for cardiovascular disease. Recent advances include the identification of factors in the synthesis and secretion of triglyceride rich lipoproteins, chylomicrons (CM) and very low density lipoproteins (VLDL). These included the identification of microsomal transfer protein, the cotranslational targeting of apoproteinB (apoB) for degradation regulated by the availability of lipids, and the characterization of transport vesicles transporting primordial apoB containing particles to the Golgi. The lipase maturation factor 1, glycosylphosphatidylinositol-anchored high density lipoprotein binding protein 1 and an angiopoietin-like protein play a role in lipoprotein lipase (LPL)-mediated hydrolysis of secreted CMs and VLDL so that the right amount of fatty acid is delivered to the right tissue at the right time. Expression of the low density lipoprotein (LDL) receptor is regulated at both transcriptional and post-transcriptional level. Proprotein convertase subtilisin/kexin type 9 (PCSK9) has a pivotal role in the degradation of LDL receptor. Plasma remnant lipoproteins bind to specific receptors in the liver, the LDL receptor, VLDL receptor and LDL receptor-like proteins prior to removal from the plasma. Reverse cholesterol transport occurs when lipid free apoAI recruits cholesterol and phospholipid to assemble high density lipoprotein (HDL) particles. The discovery of ABC transporters (ABCA1 and ABCG1) and scavenger receptor class B type I (SR-BI) provided further information on the biogenesis of HDL. In humans HDL-cholesterol can be returned to the liver either by direct uptake by SR-BI or through cholesteryl ester transfer protein exchange of cholesteryl ester for triglycerides in apoB lipoproteins, followed by hepatic uptake of apoB containing particles. Cholesterol content in cells is regulated by several transcription factors, including the liver X receptor and sterol regulatory element binding protein. This review summarizes recent advances in knowledge of the molecular mechanisms regulating lipoprotein metabolism.

Progress on the labeling and single-particle tracking technologies of viruses

The Analyst ◽  
2014 ◽  
Vol 139 (13) ◽  
pp. 3336-3346 ◽  
Author(s):  
Li-Li Huang ◽  
Hai-Yan Xie
Keyword(s):  
Fluorescence Imaging ◽  
Particle Tracking ◽  
Single Particle ◽  
Single Particle Tracking ◽  
Imaging Technologies ◽  
Recent Advances

We review recent advances in virus labeling and the emerging fluorescence imaging technologies used in the imaging and tracking of viruses.

scholarly journals High-Density Single Particle Tracking on the Plasma Membrane using High-Speed Hyperspectral Imaging

2012 ◽  
Vol 102 (3) ◽  
pp. 581a
Author(s):  
Patrick J. Cutler ◽  
Michael D. Malik ◽  
Sheng Liu ◽  
Jason M. Byars ◽  
Diane S. Lidke ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Hyperspectral Imaging ◽  
Particle Tracking ◽  
Single Particle ◽  
High Speed ◽  
Single Particle Tracking ◽  
High Density

Axisymmetric Endwall Contouring in a Four-Stage Turbine: Comparison of Experimental and Numerical Results

2002 ◽  
Author(s):  
Dieter E. Bohn ◽  
Norbert Su¨rken ◽  
Qing Yu ◽  
Franz Kreitmeier
Keyword(s):  
Flow Field ◽  
Positive Influence ◽  
Secondary Flows ◽  
Navier Stokes ◽  
Flow Measurements ◽  
Flow Angle ◽  
Numerical Predictions ◽  
Before And After ◽  
Endwall Contouring ◽  
Aerodynamic Losses

Secondary flows and leakage flows lead to complex vortex structures in the 3-D flow field of a turbine blading. Aerodynamic losses are the consequence. Reducing these aerodynamic losses by axisymmetric endwall contouring is the subject of a current experimental and numerical investigation of the flow field in a 4-stage test turbine with repeating stages. Numerical 4-stage simulations for the reconstructed turbine with an axisymmetric off-set arc endwall contour at the casing have been performed and compared to corresponding numerical investigations of the original machine without endwall modifications. The 3-D flow fields have been calculated by application of a steady 3-D Navier-Stokes code. Based on these results the experimental setup is modified to the off-set arc endwall design. The characteristics of the reconstructed machine are measured and compared to the original test rig. Special emphasis is put on the determination of the aerodynamic efficiencies over the four stages. For a detailed assessment of the radial and spanwise flow field properties inside the blading, 5-hole pressure probes are used for steady flow measurements in the narrow axial gaps before and after the 3rd stage. Finally, the measured radial distributions of the flow field properties and the machine characteristics are compared to the corresponding numerical predictions. All results show a significant positive influence of the endwall contouring on the radial distribution of the flow angle, the pressure field and the aerodynamic efficiency.

Gas Flow Measurements by 3D Particle Tracking Velocimetry Using Coloured Tracer Particles

2011 ◽  
Vol 88 (3) ◽  
pp. 343-365 ◽  
Author(s):  
Dominique Tarlet ◽  
Christian Bendicks ◽  
Christoph Roloff ◽  
Róbert Bordás ◽  
Bernd Wunderlich ◽  
...  
Keyword(s):  
Particle Tracking ◽  
Particle Tracking Velocimetry ◽  
Gas Flow ◽  
Flow Measurements ◽  
Tracer Particles

Effect of Supply Air Temperature on Rack Cooling in a High Density Raised Floor Data Center Facility

2011 ◽  
Author(s):  
Pramod Kumar ◽  
Vikneshan Sundaralingam ◽  
Yogendra Joshi ◽  
Michael K. Patterson ◽  
Robin Steinbrecher ◽  
...  
Keyword(s):  
Flow Field ◽  
Air Temperature ◽  
Data Center ◽  
Flow Distribution ◽  
High Density ◽  
Flow Measurements ◽  
Air Inlet ◽  
Air Temperatures ◽  
Tile Flow ◽  
Temperature Maps

In this paper we experimentally investigate the effect of supply air temperature on rack cooling in a high density raised floor data center facility. A series of experiments are performed on a 42 U (1-U = 4.45 cm) rack populated with 1-U servers. Desired rack heat loads are achieved by managing the distribution of server compute load within the rack. During the present experiments, temperatures at various locations in the hot and cold aisle corresponding to the rack air inlet and outlet are recorded. The temperatures are measured using a grid consisting of 256 thermocouples. The temperature measurements are further complimented with the flow field at the rack inlet. Particle Image Velocimetry (PIV) technique is used to capture the flow field at the rack inlet. The temperature maps in concert with the PIV flow field help in quantifying the rack cooling effectiveness. The temperature and flow measurements are measured for various cases by altering the supply air temperatures and perforated tile flow rates. The results are analyzed and compared with the ASHRARE recommended guidelines to arrive at the optimum supply air temperature. A perceptible change in the temperature and flow distribution is observed for the six cases investigated.

Calculation of Debris Trajectories During High-Speed Snowplowing

2002 ◽  
Author(s):  
H. K. Nakhla ◽  
B. E. Thompson
Keyword(s):  
Particle Tracking ◽  
High Speed ◽  
Turbulence Modeling ◽  
Stokes Equations ◽  
Cutting Edge ◽  
Navier Stokes ◽  
Engineering Model ◽  
Navier Stokes Equations ◽  
Snow Plowing ◽  
Reynolds Averaged Navier Stokes

An engineering model is presented to calculate the trajectory of airborne debris that adversely affects visibility during high-speed snow plowing. Reynolds-averaged Navier-Stokes equations are solved numerically with turbulence-modeling, particle-tracking, and cutting-edge approximations. Results suggest snow can be divided into splash and snow-cloud when designing treatments to improve visibility for snowplow drivers and following traffic. Calculated results confirm the findings of windtunnel and road tests, specifically that the trap angle of overplow deflectors should be less than 50 degrees to eliminate snow debris blowing over top of the plow onto the windscreen.

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