scholarly journals Temperature Measurement of Fluid Flows by Using a Focusing Schlieren Method

Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 12 ◽  
Author(s):  
A. Martínez-González ◽  
D. Moreno-Hernández ◽  
J. Guerrero-Viramontes ◽  
M. León-Rodríguez ◽  
J. Zamarripa-Ramírez ◽  
...  
Keyword(s):  
Fluid Flows ◽  
Calibration Procedure ◽  
Temperature Fields ◽  
Schlieren Image ◽  
Intensity Level ◽  
Schlieren Method ◽  
Schlieren Technique ◽  
Hot Air ◽  
Air Gun ◽  
Experimental Values

A method for measuring planar temperature fields of fluid flows is proposed. The focusing schlieren technique together with a calibration procedure to fulfill such a purpose is used. The focusing schlieren technique uses an off-axis circular illumination to reduce the depth of focus of the optical system. The calibration procedure is based on the relation of the intensity level of each pixel of a focused schlieren image to the corresponding cutoff grid position measured at the exit focal plane of the schlieren lens. The method is applied to measure planar temperature fields of the hot air issuing from a 10 mm diameter nozzle of a commercial Hot Air Gun Soldering Station Welding. Our tests are carried out at different temperature values and different planes along the radial position of the nozzle of the hot air. The experimental values of temperature measurements are in agree with those measured using a thermocouple.

scholarly journals Temperature Measurement of Fluids Flow by Using a Focusing Schlieren Method

2018 ◽  
Author(s):  
Adrián Martínez-González ◽  
David Moreno-Hernández ◽  
J. Ascención Guerrero-Viramontes ◽  
Miguel León-Rodríguez ◽  
J. Carlos I. Zamarripa-Ramírez ◽  
...  
Keyword(s):  
Calibration Procedure ◽  
Temperature Fields ◽  
Schlieren Image ◽  
Intensity Level ◽  
Depth Of Focus ◽  
Schlieren Method ◽  
Schlieren Technique ◽  
Hot Air ◽  
Air Gun ◽  
Grid Position

In this work, we propose a method to measure planar temperature fields of fluids flow. We used a focusing schlieren technique together with a calibration procedure to fulfill such purpose. The focusing schlieren technique uses an off-axis circular illumination to reduce the depth of focus of the optical system. The calibration procedure is based on the relation of the intensity level of each pixel of a focused schlieren image to the corresponding cutoff grid position measured at the exit focal plane of the schlieren lens.  The method is applied to measure planar temperature fields of the hot air issuing from a 10 mm diameter nozzle of a commercial Hot Air Gun Soldering Station Welding. Our tests are carried out at different temperature values and different planes along the radial position of the nozzle of the Hot Air Gun Soldering Station Welding. The temperature values obtained experimentally are in agreed with those obtained with a thermocouple.

scholarly journals A novel approach involving a microcatheter tip during aneurysmal coil embolization: The Γ (gamma) tip method

2019 ◽  
Vol 25 (6) ◽  
pp. 681-684 ◽  
Author(s):  
Tomotaka Ohshima ◽  
Shigeru Miyachi ◽  
Naoki Matsuo ◽  
Reo Kawaguchi ◽  
Ryuya Maejima ◽  
...  
Keyword(s):  
Coil Embolization ◽  
Parent Artery ◽  
Hot Air ◽  
Dynamic Movement ◽  
Air Gun ◽  
Novel Approach ◽  
Endovascular Coil Embolization ◽  
Aneurysmal Neck ◽  
Novel Strategy

Complete and secure occlusion of the entire aneurysmal neck remains a problem despite major advances in the treatment of intracranial aneurysms using endovascular coil embolization. Here, we present our initial clinical experience using a novel strategy for endovascular coil embolization involving a microcatheter tip, known as the “Γ (gamma) tip method,” and compare the in vitro results of this technique with those of conventional straight microcatheters. The microcatheters were bent at a right angle starting 1–2 mm from the length of the tip using a catheter-shaping mandrel and a hot air gun. The tiny right-angled tip is the “Γ tip.” In aneurysm models, we assessed the efficacy of shaping during coil deployment. The Γ-tipped microcatheters demonstrated better movement and oscillation during insertion of the coil into the aneurysm compared with the straight-tipped catheters. Moreover, the Γ-tipped microcatheter provided less coil protrusion into the parent artery and less microcatheter kickback compared with the straight tip. With the Γ-tipped microcatheter, even if the first coil loop migrated into the parent artery, its subsequent dynamic movement routed it back into the aneurysm. The Γ tip method enabled smooth movement of the microcatheter into the aneurysm, demonstrating the safety and security of coil insertion using the Γ tip compared with the conventional straight tip.

Braking System Cooling Time Simulation

2003 ◽  
Author(s):  
Luiz Tobaldini Neto ◽  
Ramon Papa ◽  
Luis C. de Castro Santos
Keyword(s):  
Stokes Equations ◽  
Thermal Environment ◽  
Computational Cost ◽  
Calibration Procedure ◽  
Accurate Solution ◽  
Temperature Fields ◽  
Convection Flow ◽  
Time Interval ◽  
Braking System ◽  
The Impact

Aircraft braking pads are subject to an extremely severe thermal environment. During a typical landing the carbon brake pads can reach temperatures up to 700–800 K or even more. Between landings during the taxi and parking phase the brakes have to cool off back to their operational limits in a time interval consistent with the average operational time. In order to evaluate the impact of design modifications on the wheel mounting and fairings, without the need of extensive laboratory and flight campaigns, a CFD (Computational Fluid Dynamics) based methodology was developed. Due to the geometry complexity the need of a geometrically representative, but simplified model comes up, in order to capture the major features of the natural convection flow and temperature fields and can be used to evaluate the influence of design changes on the braking system cooling times. A calibration procedure is carried out, aiming a better representation of the transient phenomenon, using a thermal resistances setting up feature from the solver used. An example of the application of this methodology is presented. A computational grid of over 700,000 tetrahedral elements was constructed and the Navier-Stokes equations are solved using a commercial package (FLUENT). The computational cost for a time accurate solution demands the use of parallel processing in order to complete the analysis in a typical industrial environment timeframe. Comparison with both laboratory and flight data calibrate and validate the results of the computational model. This paper describes the details of the construction of the CFD model, the setting of the initial and boundary conditions and the comparison between measured and simulated parameters.

Calibration Procedure for Attenuation Coefficient Measurements in Highly Opaque Media Using Infrared Focal Plane Array (IRFPA) Spectroscopy

2018 ◽  
Vol 72 (2) ◽  
pp. 177-187 ◽  
Author(s):  
Sara Kirchner ◽  
Sebastien Narinsamy ◽  
Alain Sommier ◽  
Marta Romano ◽  
Meguya Ryu ◽  
...  
Keyword(s):  
Coming Out ◽  
Focal Plane ◽  
Aqueous Media ◽  
Focal Plane Array ◽  
Calibration Procedure ◽  
Integration Time ◽  
Intensity Level ◽  
Infrared Focal Plane Array ◽  
Ir Spectroscopic

The purpose of this article is to present a new calibration procedure for spectroscopic measurements using an infrared focal plane array (IRFPA) spectrometer on highly opaque middle-wave infrared (MWIR) media. The procedure is based on the properties of the IRFPA camera and especially the integration time (IT), which is the main parameter that can be adjusted to control the sensitivity of the measurements. The goal of the paper is to experimentally validate this dependence with the direct reference intensity light coming out of the IR monochromator in order to predict the spectrum shape and intensity level in a range out of the camera saturation. This method allows determining spectrum used as background for transmittance calculation. It has been applied in the case of measurement of water transmittance, which is a highly opaque medium and whose measurement requires high ITs. The main result is the ability to take an IR spectroscopic imaging measurement through 300 µm of water and the determination of its transmittance with sufficient sensitivity due to the proposed calibration procedure. This procedure allows the possibility of transitory studies in heterogeneous aqueous media.

Insulation Systems of Frameless Buildings

2020 ◽  
Vol 992 ◽  
pp. 66-72
Author(s):  
Ekaterina Yu. Bobrova ◽  
K.A. Ter-Zakaryan ◽  
Alexey D. Zhukov ◽  
A.A. Medvedev ◽  
A.I. Poserenin
Keyword(s):  
Thermal Imaging ◽  
Weld Seam ◽  
Raw Material ◽  
Environmental Friendliness ◽  
Longitudinal Tensile Strength ◽  
Hot Air ◽  
Air Gun ◽  
Insulation Systems ◽  
Metallized Coating ◽  
Side Walls

The article analyzes different ways of creating an insulating coating within the scope of frameless buildings. Among such constructions, the production halls, raw material and finished-products storages, agricultural storages, livestock housing, garages, covered parking, sports and cultural facilities are to be distinguished. Criteria that the heat-insulating materials should meet in the context of effective and durable insulation coatings are low thermal conductivity, vapor and water permeability, high operational durability and environmental friendliness as well. It is confirmed that products based on polyethylene foam, such as mats and rolls, fully meet the above-mentioned criteria. Furthermore, the possibility of obtaining a seamless joint during the installation process significantly increases the effectiveness of the insulating coating by means of minimizing cold bridges and eliminating leakages when connecting separate insulating elements. Polyethylene foam is an elastic and well stretching material. When fixing polyethylene foam rolls on the metal covering of the frameless construction, they will change their shape together with the metal due to the climatic temperature drops (stretch and constrict). The performed tests have revealed that the longitudinal tensile strength of the products with a metallized coating is 80–92 kPa, without a metallized coating - 80–87 kPa, and 29–32 kPa of the weld seam. The article includes information regarding the results of thermal imaging monitoring of frameless constructions with an insulating coating based on polyethylene foam. It is shown that hot-air welding (with the help of a hot air gun) allows minimizing heat losses both at the joints of the sheets and in the areas adjoining to the base and to the side walls of the buildings.

scholarly journals Gas-Vapor Mixture Temperature in the Near-Surface Layer of a Rapidly-Evaporating Water Droplet

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 803
Author(s):  
Antonov ◽  
Volkov ◽  
Strizhak
Keyword(s):  
High Temperature ◽  
Temperature Fields ◽  
Vapor Mixture ◽  
Water Droplets ◽  
Unsteady Temperature ◽  
Near Surface ◽  
Planar Laser ◽  
Steady Temperature Field ◽  
Experimental Values ◽  
High Temperature Gas

Mathematical modeling of the heat and mass transfer processes in the evaporating droplet–high-temperature gas medium system is difficult due to the need to describe the dynamics of the formation of the quasi-steady temperature field of evaporating droplets, as well as of a gas-vapor buffer layer around them and in their trace during evaporation in high-temperature gas flows. We used planar laser-induced fluorescence (PLIF) and laser-induced phosphorescence (LIP). The experiments were conducted with water droplets (initial radius 1–2 mm) heated in a hot air flow (temperature 20–500 °С, velocity 0.5–6 m/s). Unsteady temperature fields of water droplets and the gas-vapor mixture around them were recorded. High inhomogeneity of temperature fields under study has been validated. To determine the temperature in the so called dead zones, we solved the problem of heat transfer, in which the temperature in boundary conditions was set on the basis of experimental values.

On-line Consolidation of Commingled Polypropylene/Glass Roving During Filament Winding

2011 ◽  
Vol 24 (6) ◽  
pp. 789-804 ◽  
Author(s):  
R. Gennaro ◽  
F. Montagna ◽  
A. Maffezzoli ◽  
F. Fracasso ◽  
S. Fracasso
Keyword(s):  
Filament Winding ◽  
Void Content ◽  
Processing Conditions ◽  
Hot Air ◽  
Air Gun ◽  
On Line ◽  
Set Up ◽  
Comparison Of The Results ◽  
Composite Samples

In this study, the in situ consolidation of polypropylene matrix/glass reinforced rovings was performed combining two heating systems, an infrared oven and a hot air gun, and a roll pressing the commingled roving during hoop winding on a cylindrical mandrel. Process parameters were set up on the basis of a preliminary simulation of the heat transfer along the roving and then comparison of the results with experimental temperature profiles obtained by a noncontact thermometer. Composite samples were cut along the cylinder axis for mechanical characterization. Physical properties, such as density and void content, obtained using different processing conditions, were compared. Electron microscopy was performed in order to assess how processing conditions affect fiber–matrix impregnation.

Optimization of Six Strand Tundish Based on Flow and Temperature

2011 ◽  
Vol 239-242 ◽  
pp. 1846-1849
Author(s):  
Sheng Li Li ◽  
Xin Gang Ai ◽  
Dong Wei Zhang ◽  
Nan Lv ◽  
Xiao Dong Hu
Keyword(s):  
Fluid Flow ◽  
Physical Modeling ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Fluid Flows ◽  
Temperature Fields

In this paper the fluid flow and temperature are used together to optimize the 40 tons six strand tundish. Fluid flows in a six strand tundish have been investigated with physical modeling, then steady, three-dimensional temperature fields inside the six strand tundish are obtained. The physical modeling experiments give two optimal integrated tundish structural parameters of baffle holes. From the further study of temperature fields, the tundish should be optimized in the structural parameters of baffle holes in the condition of height 300mm, angel 30° and diameter 20mm.

Use of the schlieren method to investigate temperature fields in a solid

1971 ◽  
Vol 20 (3) ◽  
pp. 372-374 ◽  
Author(s):  
Yu. A. Napar'in ◽  
V. I. Shakhurdin
Keyword(s):  
Temperature Fields ◽  
Schlieren Method

scholarly journals INVESTIGATING ON EFFECT OF HOT AIR AND WATER TEMPERATURE ON KINETIC OF REHYDRATION OF CELERY BY USING PELEG’S MODEL

2019 ◽  
Vol 49 (4) ◽  
pp. 249-254
Author(s):  
Azadeh Salimi ◽  
Haniyeh Ameri ◽  
Atefe Hajigorbani
Keyword(s):  
Moisture Content ◽  
Water Temperature ◽  
Absorption Capacity ◽  
Water Absorption Capacity ◽  
Hot Air ◽  
Peleg Model ◽  
Experimental Values ◽  
Drying Conditions ◽  
Kinetics Of ◽  
Determine Effect

The Peleg model was used to determine effect of drying conditions and rehydration water temperature on kinetic of moisture content and rehydration ration changes of celery. Celery cubes (1×1×1 cm) were dried at 65ºC in hot air oven. Samples were rehydrated by immersion in water during different periods of time and temperatures (25±2ºC and 100±2ºC). Rehydration kinetic was monitored by measuring samples' weights at regular intervals. Results showed that the highest final moisture content which was observed belonged to the samples which were dried at 70 °C and reydrated at 25°C water temperature, also, dried celeries which were rehydrated at a water temperature of 25°C, had higher levels of RR as a function of physical properties. The Peleg’s e constant (K1), decreased significantly while water temperature increased and in case of the Peleg capacity constant (K2), it increased slightly while water temperature increased. Decreasing of K2 values is a sign of more water absorption capacity. Finally, it was observed that the predicted and experimental values had a good correlation which indicates that the Peleg model is adequate to describe rehydration kinetics of celery cubes.

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