Three-Dimensional Velocity and Temperature Field Measurements of Internal and External Turbine Blade Features Using Magnetic Resonance Thermometry

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Michael J. Benson ◽  
Bret P. Van Poppel ◽  
Christopher J. Elkins ◽  
Mark Owkes
Keyword(s):  
Reynolds Number ◽  
Temperature Field ◽  
Magnetic Resonance ◽  
Turbine Blade ◽  
Flow Line ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Fluid Temperature ◽  
Magnetic Resonance Thermometry

Magnetic resonance thermometry (MRT) is a maturing diagnostic tool used to measure three-dimensional temperature fields. It has a great potential for investigating fluid flows within complex geometries leveraging medical grade magnetic resonance imaging (MRI) equipment and software along with novel measurement techniques. The efficacy of the method in engineering applications increases when coupled with other well-established MRI-based techniques such as magnetic resonance velocimetry (MRV). In this study, a challenging geometry is presented with the direct application to a complex gas turbine blade cooling scheme. Turbulent external flow with a Reynolds number of 136,000 passes a hollowed NACA-0012 airfoil with internal cooling features. Inserts within the airfoil, fed by a second flow line with an average temperature difference of 30 K from the main flow and a temperature-dependent Reynolds number in excess of 1,800, produces a conjugate heat transfer scenario including impingement cooling on the inside surface of the airfoil. The airfoil cooling scheme also includes zonal recirculation, surface film cooling, and trailing edge ejection features. The entire airfoil surface is constructed of a stereolithography resin—Accura 60—with low thermal conductivity. The three-dimensional internal and external velocity field is measured using an MRV. The fluid temperature field is measured within and outside of the airfoil with an MRT, and the results are compared with a computational fluid dynamics (CFD) solution to assess the current state of the art for combined MRV/MRT techniques for investigating these complex internal and external flows. The accompanying CFD analysis provides a prediction of the velocity and temperature fields, allowing for errors in the MRT technique to be estimated.

Three Dimensional Velocity and Temperature Field Measurements of Internal and External Turbine Blade Features Using Magnetic Resonance Thermometry

2018 ◽  
Author(s):  
Michael J. Benson ◽  
Bret P. Van Poppel ◽  
Christopher J. Elkins ◽  
Mark Owkes
Keyword(s):  
Reynolds Number ◽  
Temperature Field ◽  
Magnetic Resonance ◽  
Turbine Blade ◽  
Flow Line ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Fluid Temperature ◽  
Magnetic Resonance Thermometry

Magnetic Resonance Thermometry (MRT) is a maturing diagnostic used to measure three-dimensional temperature fields. It has great potential for investigating fluid flows within complex geometries leveraging medical grade MRI equipment and software along with novel measurement techniques. The efficacy of the method in engineering applications increases when coupled with other well established MRI-based techniques such as Magnetic Resonance Velocimetry (MRV). In this study, a challenging geometry is presented with direct application to a complex gas turbine blade cooling scheme. Turbulent external flow with a Reynolds number of 136,000 passes a hollowed NACA-0012 airfoil with internal cooling features. Inserts within the airfoil, fed by a second flow line with an average temperature difference of 30 K from the main flow and a temperature-dependent Reynolds number in excess of 1,800, produce a conjugate heat transfer scenario including impingement cooling on the inside surface of the airfoil. The airfoil cooling scheme also includes zonal recirculation, surface film cooling, and trailing edge ejection features. The entire airfoil surface is constructed of a stereolithography resin — Accura 60 — with low thermal conductivity. The three-dimensional internal and external velocity field is measured using MRV. The fluid temperature field is measured within and outside of the airfoil with MRT and the results are compared with a computational fluid dynamics (CFD) solution to assess the current state of the art for combined MRV/MRT techniques for investigating these complex internal and external flows. The accompanying CFD analysis provides a prediction of the velocity and temperature fields, allowing for errors in the MRT technique to be estimated.

Magnetic Resonance Thermometry: An Emerging Three-Dimensional Temperature Diagnostic Technique

2019 ◽  
Author(s):  
Michael J. Benson ◽  
Mattias Cooper ◽  
Bret P. Van Poppel ◽  
Christopher J. Elkins
Keyword(s):  
Temperature Field ◽  
Data Analysis ◽  
Magnetic Resonance ◽  
Data Processing ◽  
Water Channel ◽  
Three Dimensional ◽  
Diagnostic Technique ◽  
The Other ◽  
Temperature Measurements ◽  
Magnetic Resonance Thermometry

Abstract Magnetic Resonance Thermometry (MRT) is a developing diagnostic technique that leverages advanced medical technologies to accurately measure the temperature of a fluid flow within and around complex geometries. The full three-dimensional temperature field obtained by MRT can be used to analyze heat transfer characteristics and potentially investigate thermal boundary layers near arbitrarily complex surfaces. This technique requires neither optical nor physical accessibility, thereby enabling a wide range of engineering applications. This paper describes the current state of the art for MRT measurement, detailing turbulent water channel tests, materials selection, scanning parameters, data analysis of time-averaged temperature measurements, and uncertainty estimates. The purpose of this work was to evaluate and refine the MRT technique to increase the accuracy of temperature measurements and minimize the error in fully turbulent flow measurements. In the present study, a plate with a vertical cylinder extending from both of its sides was placed between two channels, and a diagonal hole was drilled through the cylinder from one side of the plate to the other. This enabled fluid from one channel to mix with the fluid in the other. This experiment studied the mixing of two fluids at different temperatures. The upstream temperatures of each fluid were measured with thermocouples. Both flows were fully turbulent, and the colder temperature channel had a Reynolds number of 11,800. Tests were run with four different fluid temperatures for calibration and to determine any temperature dependence of measurements. Three-dimensional temperature field measurements are reported and details about data processing and procedures to conduct the experiments are provided. This work resulted in several notable improvements to MRT experimental methods. The test section and water channel were designed to limit the effects of thermal expansion in the stereolithography materials used for manufacturing the complex internal flow geometry. Multiple echo scans were used to minimize the effects of magnetic field drift commonly observed in extended scanning periods in MRI systems. Data analysis techniques were used to quantify expansion effects for both hot and cold flow cases. To quantify measurement uncertainty, the standard deviation of the mean was calculated at each data point across different scan numbers and confidence intervals established using a student t-test. An improved data processing code was used to filter data resulting in increased measurement accuracy and reduced uncertainty to less than 1 °C for most of the domain. Future work will further refine the experimental techniques to improve scanning procedures, employ high conductivity ceramics and larger geometries with relevant applications, and simplify data processing methods to generate full-field flow temperature data.

Magnetic Resonance Thermometry Experimental Setup: A Portable Heat Transfer Experiment

2016 ◽  
Author(s):  
Elliott T. Williams ◽  
Jonathan R. Spirnak ◽  
Marc C. Samland ◽  
Brant G. Tremont ◽  
Alfred L. McQuirter ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Turbulent Flows ◽  
Imaging System ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Cross Flow ◽  
Experimental Setup ◽  
Magnetic Resonance Imaging System ◽  
Magnetic Resonance Thermometry ◽  
Jet Mixing

This work provides a detailed description of the setup and execution of an experiment employing Magnetic Resonance Thermometry (MRT) techniques for measuring the three-dimensional temperature field of a fully turbulent jet mixing with a cross flow. The proposed methodology has the flexibility of applying different thermal boundary conditions — adiabatic and conductive — by varying the materials used in the test section as well as varying the temperatures of the mixing flows. The experiment described in this paper employs a standard magnetic resonance imaging system comparable to those used in medical radiology departments worldwide. A series of MR scans with both isothermal and thermal mixing conditions were conducted and results are presented with sub-millimeter resolution across the measured 3D domain of interest within one degree Celsius. The methodology presented here holds unique advantages over conventional techniques because measurements can be acquired without introducing flow disturbances and in regions without any optical access. When coupled with other established MR-based measurement techniques, MRT provides large, robust data sets that can be used for validation, design, and insight into system thermal performance for complex, turbulent flows. The materials and components employed in this work cost approximately $13,900, and the experimental setup and data collection required approximately 48 hours.

scholarly journals Impact of Tunnel Temperature Variations on Surrounding Rocks in Cold Regions

2019 ◽  
Author(s):  
Qingyang Yu ◽  
Chao Zhang ◽  
Zhenxue Dai ◽  
Chao Du ◽  
Mohamad Reza Soltanian ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Insulation Layer ◽  
Cold Regions ◽  
Ambient Temperatures ◽  
Temperature Conditions ◽  
Layer Control

Temperature is an important factor in designing and maintaining tunnels, especially in cold regions. We present three-dimensional numerical simulations of tunnel temperature fields at different temperature conditions. We study the tunnel temperature field in two different conditions with relatively low and high ambient temperatures representing winter and summer of northeast China. We specifically study how these temperature conditions affect tunnel temperature and its migration to surrounding rocks. We show how placing an insulation layer could affect the temperature distribution within and around tunnels. Our results show that the temperature field without using an insulation layer is closer to the air temperature in the tunnel, and that the insulation layer has shielding effects and could plays an important role in preventing temperature migration to surrounding rocks. We further analyzed how thermal conductivity and thickness of insulation layer control the temperature distribution. The thermal conductivity and thickness of insulation layer only affect the temperature of the surrounding rocks which are located at distances below ~20 m from the lining.

Lattice Boltzmann Study of Flow and Temperature Structures ofNon-Isothermal Laminar Impinging Streams

2013 ◽  
Vol 13 (3) ◽  
pp. 835-850 ◽  
Author(s):  
Wenhuan Zhang ◽  
Zhenhua Chai ◽  
Zhaoli Guo ◽  
Baochang Shi
Keyword(s):  
Boundary Condition ◽  
Reynolds Number ◽  
Temperature Field ◽  
Prandtl Number ◽  
Lattice Boltzmann ◽  
Periodic Structures ◽  
Temperature Fields ◽  
Buoyancy Effect ◽  
Practical Applications ◽  
Boltzmann Method

AbstractPrevious works on impinging streams mainly focused on the structures of flow field, but paid less attention to the structures of temperature field, which are very important in practical applications. In this paper, the influences of the Reynolds number (Re) and Prandtl number (Pr) on the structures of flow and temperature fields of non-isothermal laminar impinging streams are both studied numerically with the lattice Boltzmann method, and two cases with and without buoyancy effect are considered. Numerical results show that the structures are quite different in these cases. Moreover, in the case with buoyancy effect, some new deflection and periodic structures are found, and their independence on the outlet boundary condition is also verified. These findings may help to understand the flow and temperature structures of non-isothermal impinging streams further.

scholarly journals Three-dimensional temperature and velocity measurements in fluids using thermographic phosphor tracer particles

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Moritz Stelter ◽  
Fabio J. W. A. Martins ◽  
Frank Beyrau ◽  
Benoît Fond
Keyword(s):  
Gas Flow ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Fluid Temperature ◽  
Velocity Measurements ◽  
Tomographic Piv ◽  
Tracer Particles ◽  
Thermographic Phosphor ◽  
Wide Range ◽  
Ratio Imaging

Many flows of technical and scientific interest are intrinsically three-dimensional. Extracting slices using planar measurement techniques allows only a limited view into the flow physics and can introduce ambiguities while investigating the extent of 3D regions. Nowadays, thanks to tremendous progress in the field of volumetric velocimetry, full 3D-3C velocity information can be gathered using tomographic PIV or PTV hence eliminating many of these ambiguities (Discetti and Coletti, 2018; Westerweel et al., 2013). However, for scalar quantities like temperature, 3D measurements remain challenging. Previous approaches for coupled 3D thermometry and velocimetry combined astigmatism PTV with encapsulated europium chelates particles (Massing et al., 2018) or tomographic PIV with thermochromic liquid crystals particles (Schiepel et al., 2021). Here we present a new technique based on solid thermographic phosphor tracer particles, which have been extensively used for planar fluid temperature and velocity measurements (Abram et al., 2018) and are applicable in a wide range of temperatures. The particles are seeded into a gas flow where their 3D positions are retrieved by triangulation from multiple views and their temperatures are derived from two-colour luminescence ratio imaging. In the following, the experimental setup and key processing steps are described before a demonstration of the concept in a turbulent heated jet is shown.

scholarly journals Laser interferometry - Report #HT-01-2017

2021 ◽  
Author(s):  
David Naylor
Keyword(s):  
Heat Transfer ◽  
Light Beam ◽  
Three Dimensional ◽  
Local Heat Transfer ◽  
Laser Interferometry ◽  
Local Heat ◽  
Temperature Fields ◽  
Fluid Temperature ◽  
Two Dimensional ◽  
Transfer Rates

An introduction is given to the optical setup and principle of operation of classical and holographic interferometers that are used for convective he at transfer measurements. The equations for the evaluation of the temperature field are derived and methods of analysis are discussed for both two-dimensional and three-dimensional temperature fields. Emphasis is given to techniques for measuring local heat transfer rates. For two-dimensional fields, a method is presented for measuring the surface temperature gradient directly from a finite (wedge) fringe interferogram. This “direct gradient method” is shown to be most useful for the measurement of low convective heat transfer rates. For three-dimensional fields, the equations for calculating the beam-averaged local heat flux are presented. The measurement of the fluid temperature averaged along the light beam is shown to be approximate. However, an analysis is presented showing that for most cases the error associated with temperature variations in the light beam direction is small. Digital image analysis of interferograms to obtain fringe spacings is also discussed briefly.

Direct Numerical Simulation of Flow and Heat Transfer From a Sphere in a Uniform Cross-Flow

2000 ◽  
Vol 123 (2) ◽  
pp. 347-358 ◽  
Author(s):  
P. Bagchi ◽  
M. Y. Ha ◽  
S. Balachandar
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Vortex Shedding ◽  
Axisymmetric Flow ◽  
Three Dimensional ◽  
Cross Flow ◽  
Reynolds Numbers ◽  
Temperature Fields ◽  
Flow And Heat Transfer

Direct numerical solution for flow and heat transfer past a sphere in a uniform flow is obtained using an accurate and efficient Fourier-Chebyshev spectral collocation method for Reynolds numbers up to 500. We investigate the flow and temperature fields over a range of Reynolds numbers, showing steady and axisymmetric flow when the Reynolds number is less than 210, steady and nonaxisymmetric flow without vortex shedding when the Reynolds number is between 210 and 270, and unsteady three-dimensional flow with vortex shedding when the Reynolds number is above 270. Results from three-dimensional simulation are compared with the corresponding axisymmetric simulations for Re>210 in order to see the effect of unsteadiness and three-dimensionality on heat transfer past a sphere. The local Nusselt number distribution obtained from the 3D simulation shows big differences in the wake region compared with axisymmetric one, when there exists strong vortex shedding in the wake. But the differences in surface-average Nusselt number between axisymmetric and three-dimensional simulations are small owing to the smaller surface area associated with the base region. The shedding process is observed to be dominantly one-sided and as a result axisymmetry of the surface heat transfer is broken even after a time-average. The one-sided shedding also results in a time-averaged mean lift force on the sphere.

Three-Dimensional Analytical Temperature Field Around the Welding Cavity Produced by a Moving Distributed High-Intensity Beam

1993 ◽  
Vol 115 (4) ◽  
pp. 848-856 ◽  
Author(s):  
P. S. Wei ◽  
M. D. Shian
Keyword(s):  
Temperature Field ◽  
Power Density ◽  
High Power ◽  
Three Dimensional ◽  
Second Law Of Thermodynamics ◽  
Temperature Fields ◽  
Momentum Balance ◽  
High Power Density ◽  
Depth Of Penetration ◽  
Confluent Hypergeometric Functions

An analytical solution for the three-dimensional temperature field in the liquid and heat-affected zones around a welding cavity produced by a moving distributed low- or high-power-density-beam is provided. The incident energy rate distribution is assumed to be Gaussian and the cavity is idealized by a paraboloid of revolution in workpieces of infinite, semi-infinite, or finite thicknesses. The present study finds that temperature fields can be described by the Laguerre and confluent hypergeometric functions. By satisfying a momentum balance at the cavity base and utilizing a consequence of the second law of thermodynamics, the depth of penetration is uniquely determined. The results show that the predicted depths and temperatures of the cavity agree with available experimental data. Some crucial factors affecting the transition from low- to high-power-density-beam welding are presented.

Analysis of Transient Heat Conduction in Complex Shaped Composite Materials

1988 ◽  
Vol 110 (2) ◽  
pp. 110-112 ◽  
Author(s):  
Seiichi Nomura ◽  
A. Haji-Sheikh
Keyword(s):  
Temperature Field ◽  
Heat Conduction ◽  
Composite Materials ◽  
Analytical Procedure ◽  
Three Dimensional ◽  
Transient Heat Conduction ◽  
Temperature Fields ◽  
Finite Region ◽  
Symbolic Algebra ◽  
The Galerkin Method

This paper addresses a generalized analytical procedure for transient heat conduction in composite materials of two- and three-dimensional finite region. The Galerkin method is employed to obtain temperature field in closed form with the utilization of symbolic algebra software such as REDUCE or MACSYMA. It is found from illustrative examples that the proposed method yields accurate and effective predictions of temperature fields for which purely numerical methods such as finite element or finite difference are not suitable.

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