bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability Analysis of an Evaporating and/or Condensing Thin Liquid Film
Authors: Chai L. H. , Peng X. F. , Ochterbeck J. M. 
Published: January 2022

Abstract
A perturbation analysis of a simplified set of the Navier-Stokes equations was conducted to investigate the transport process of an evaporating and/or condensing thin liquid film. Expression of the wave growth rate was obtained by accounting for the phase transition at the interface and surface tension gradients. Effects of the surface tension gradient and phase transition on the stability were investigated by introducing two dimensionless parameters, the Marangoni number, Ma, and the phase transition number, ζ, respectively. The present investigation also provides several reasonable theoretical explanations of the fundamental characteristics of dropwise and pseudo-dropwise condensation.
Heat Transfer Enhancement With Falling Film Evaporation on Vertical Tubes Using Electric Fields
Authors: Darabi Jafar , Ohadi Michael M. , Dessiatoun Serguie V. 
Published: January 2022

Abstract
The objective of this work is to characterize the phenomena and to identify the feasibility of the EHD technique for falling film evaporation on geometries of practical significance to industrial chillers. Single-tube experiments are conducted with refrigerants R-123 and R-134a on the outside of three commercially available vertical, electrically heated tubes. Tests are conducted with a 19 mm (3.4″) smooth tube, a 19 fpi tube, and a Turbo BIII tube. The effect of heat flux, refrigerant mass flow rate, and applied potential are investigated. Up to a 7 fold enhancement in heat transfer coefficient with R-123 and 2.1 fold with R-134a are documented. EHD power consumption in all cases is less than 0.15% of the total energy exchange rate in the test section.
Two-Dimensional Transient Analysis of Absorbing Thin Film in Laser Treatments
Authors: Bianco Nicola , Manca Oronzio 
Published: January 2022

Abstract
Conjugate optical-conductive analysis is of main importance in thin film processing applications. Several studies have been carried out by making use of the one-dimensional model. In this paper the transient conjugate conductive-radiative field has been solved in the hypothesis of one-dimensionality of the optical field and of two-dimensionality of the thermal field. Results have been obtained with the matrix method for the optical field and the finite volume method for the thermal field. The results show that when the investigation is localized to the center of the spot, the one-dimensional model describes the thermal field quite well. Instead, if knowledge of the temperature is required elsewhere the two-dimensional model is needed. The investigation herein presented shows that for low-conductivity materials (a – Si) the temperature peaks are placed inside the thin film for the absorption function distribution, determined by interference phenomena. For higher-diffusivity materials (c – Si), both the thermal gradient components are of the same order of magnitude. The laser irradiation wavelength is 1.064 μm for a – Si and 0.532 μm for c – Si.
Directional Spectral Emittance of a Packed Bed: Correlation of Theoretical Prediction and Experimental Data
Authors: Lopes Rogério , Moura Luís M. , Baillis Dominique , Sacadura Jean-François 
Published: January 2022

Abstract
Directional spectral emittance of absorbing and scattering isotherm packed spheres system is predicted by a radiative model based on the discrete ordinates method associated with the control volume technique to solve the radiative transfer equation. Radiative properties for the packed opaque spheres bed are computed by the large size parameter factor scaling model. This model requires the knowledge of several parameters. Particle diameter and porosity can be easily obtained, but particle hemispherical spectral reflectivity is very difficult to obtain directly. It is determined by an identification method (Gauss method of linearization) applied to bidirectional spectral reflectance data obtained from an experimental device using a Fourier transform infrared spectrometer. Results obtained from this approach are consistent. Directional spectral emittance of absorbing and scattering isotherm packed spheres system is predicted using a radiative model based on the discrete ordinates method to solve the radiative transfer equation. Directional spectral emittance is measured using a direct radiometric technique which has been recently proposed. A good agreement is observed between experimental results of directional spectral emittance packed opaque spheres system at high temperature and theoretical data computed.
Foundations of Thermal-Fluid Sciences: An Introductory Sophomore Course for Mechanical Engineering Majors
Authors: Gaddis J. L. , Ochterbeck J. M. 
Published: January 2022

Abstract
As part of an overall revision of the mechanical engineering curriculum at Clemson University, a new introductory course in thermal-fluid sciences was developed.1 This course is situated in the second semester, sophomore year for mechanical engineering majors, and is a prerequisite for the junior-level courses in thermodynamics and fluid mechanics. The new course introduces the mass, momentum, and energy conservation laws in addition to defining work and heat and use of thermodynamic properties. Included in the paper is information on the new curriculum, motivation for new course and sequence, decisions interacting with the curriculum, implementation of textbooks, and early results.
Towards an Integrated Thermal/Fluids Engineering Curriculum
Authors: Jensen Michael K. , Smith Richard N. , Kaminski Deborah A. , Hirsa Amir 
Published: January 2022

Abstract
We present a new approach to teaching the core thermal/fluids curriculum for undergraduate programs in engineering. Traditional thermodynamics, fluid mechanics, and heat transfer classes are being replaced with two integrated courses and a laboratory in which the three disciplines are taught simultaneously to show interconnections and transferability of concepts and ideas, with an emphasis on the way they occur in engineering practice. This approach seeks to improve both the context and manner in which the subject matter is covered. Our goals are to enhance the physical intuition of our students, to stimulate their ability to think critically and synthesize information, and to make clearer the relevance of the fundamentals to advanced analytical and computational tools.
An Integrated Thermal Science Course for Third-Year Mechanical Engineering Students
Authors: Noymer Peter D. , Hazen Megan U. , Yao S. C. 
Published: January 2022

Abstract
A new course in the thermal science discipline was introduced in 1998 in the Mechanical Engineering Department at Carnegie Mellon University. The course was titled “Thermal Fluids Engineering” and some of the specific aims were to integrate and extend the students’ knowledge in the areas of heat transfer, thermodynamics and fluid mechanics and provide better preparation for their post-graduate endeavors. The development of this course was part of a larger curriculum re-design within both the Mechanical Engineering Department and the College of Engineering at Carnegie Mellon.
The course was offered to students in the second semester of their third year, after they have taken thermodynamics, fluid mechanics and heat transfer in each of the previous three semesters. In addition to integrating the three basic thermal science disciplines, other novel aspects of this course included: a series of computational assignments in which finite-element models were applied to solve conjugate heat transfer problems; a series of laboratory experiments, one of which was used as the basis for the computational assignments; and a series of in-class “case studies” in which the students applied their integrated knowledge to the design and analysis of a complex system. Feedback from the students indicated that the integration aspect of the course was successful although there was still room for improvement in the structure and presentation of the material.
Electro-Hydrodynamic Augmentation of Heat Transport in Micro Heat Pipe Arrays
Authors: Hallinan Kevin P. , Bhagat Wilber , Kashaboina Balamurali , Kashani A. Reza 
Published: January 2022

Abstract
Research is reported on a novel use of electrostatic fields to both enhance the effectiveness of heat transport and the maximum heat transfer throughput of micro heat pipe devices. This research has sought to make practical the electro-hydrodynamic heat pipe concept proposed by T. Jones in the early 1970s, but which never was successfully developed at macroscales.
Experiments are reported which conclusively demonstrate the viability of using electrostatic fields to augment heat transfer in micro heat pipe devices. An n-pentane filled glass heat pipe array comprised of 1mm width grooves having 1mm of ‘land’ between each groove was fabricated from quartz. The heat pipe array was 25.4 mm long. Gold-palladium electrodes, approximately 100 microns in thickness, were vapor deposited on both sides of the heat pipe to allow for the application of an electrostatic field across the grooves of up to 10 kV/mm. The electrodes were semi-transparent, thereby permitting visual observation of the liquid orientation within the micro heat pipe. For a majority of experiments, however, the micro heat pipes were contained in an insulated enclosure.
The experiments indicated little difference in the micro heat pipe temperature at low heat inputs (less than 0.3 W/groove). At heat inputs sufficient to cause the onset of dry-out of the evaporator without application of the electric field, the presence of the electric field was noticeable in producing a more uniform micro heat pipe temperature and a relatively lower evaporator temperature. At increasing heat inputs, the presence of the electric field was shown to prevent evaporator dry-out for the heat inputs considered. Further, at heat inputs sufficient to cause dry-out of the evaporator without an applied electric field, the electric field contributed to an increasing heat transfer effectiveness in the evaporator as the heat input was increased.
Flow Profile Simulation of Heated Copper Films on Substrates With Micro-Trenches
Authors: Hirasawa Shigeki , Saito Yoko , Saito Tatsuyuki , Yamaguchi Hizuru 
Published: January 2022

Abstract
It is important that copper films fill the sub-micron trenches on silicon substrates in order to produce high-density electronic devices. In this paper, changes of the copper film profiles in trenches on silicon substrates during the reflow process were numerically calculated by 2- and 3-dimensional analyses. Calculation results from a model of atomic surface diffusion in a thin layer on the film were similar to experimental results. The relationship between the change of the film profile and the geometric parameters was determined. The results show that a uniform and thick initial film on the side walls of a trench is important to avoid film-bridge and void formation in the trench. In order to increase flow rate into the trenches, narrow trenches with a thick initial film on the bottom of the trench are effective.
Technique for Measuring Surface Temperature Fluctuations on a Silicon Wafer During Boiling
Authors: Kim Jungho , Whitten Matthew , Quine Richard W. , Kalkur T. S. 
Published: January 2022

Abstract
A method of measuring temperature fluctuations on a silicon wafer during boiling is described. The technique consists of building an array of diodes on a silicon wafer using VLSI techniques, and exploiting the fact that the forward voltage drop across a silicon diode typically is approximately proportional to the inverse of the absolute temperature of the diode. Once a calibration of voltage drop vs. temperature is obtained, the temperature of each diode can be obtained by scanning across the diode array. A 32 × 32 array of diodes (1024 diodes) has been built. Each diode in the array is nominally 100 μm × 100 μm in size. A circuit capable of scanning this diode array at speeds up to 2.5 MHz was also designed, built, and tested. The entire array can be sampled at speeds up to about 2.5 kHz. Construction of the diode array, the circuit, and some preliminary results are described.
Coupled Liquid and Vapor Flow in Miniature Passages With Micro Grooves
Authors: Khrustalev Dmitry , Faghri Amir 
Published: January 2022

Abstract
Friction factor coefficients for liquid flow in a rectangular microgroove coupled with the vapor flow in a vapor channel of a miniature two-phase device were calculated using finite element analysis. The results show that the effect of the vapor-liquid frictional interaction on the liquid flow decreases with curvature of the liquid-vapor interface. Shear stresses at the liquid-vapor interface are significantly non-uniform, decreasing towards the center of the liquid-vapor meniscus.
Effectiveness of Open-Cell Metallic Foams for High Power Electronic Cooling
Authors: Bastawros Ashraf-F. 
Published: January 2022

Abstract
The effectiveness of metallic foams in forced convection heat removal is studied. The metallic foam showed an improved heat removal rate with a moderate increase in the pressure drop. The hydraulic and thermal characteristics are analyzed experimentally. The measurements are used in conjunction with a model based on a bank of cylinders in cross-flow to understand the effect of various foam morphologies. The model prediction is extrapolated to examine the trade-off between heat removal and pressure drop. For a particular working fluid, the model provides two sets of design parameters; (i) a preferred foam morphology which will provide the required heat flux at a competitive pressure drop and (ii) the circulating fan characteristics as an output flow rate vs. the static pressure drop.
Design Analysis of the Stirling Engine Using an Equation Solver
Authors: Farley Jove S. , Ibrahim Osama M. 
Published: January 2022

Abstract
A typical undergraduate course in thermal-fluids design sees the unfolding of important concepts in heat transfer, thermodynamics, and fluid mechanics and associated governing laws. Unfortunately, up until the recent past students have largely been asked to study fundamental, but often elusive, topics in these areas by means of simplified problems mostly resulting in the solution of elementary sets of algebraic equations. More complex problems involving higher order equations and ordinary differential equations are left unexamined, due mostly to the time consumption and difficulty level of programming, which may detract from the scope of the class.
Fortunately, there now exists prewritten software (i.e. EES, Matlab, Mathematica, etc.) which numerically allows students to solve more challenging problems with relative ease. Thus allowing thermal-fluids design courses to focus on more challenging projects.
This paper illustrates the use of a program, written for an equation solving software package that solves the ordinary differential equations governing the processes of the Stirling engine. Stirling engines, their history and present applications along with the methods EES software uses to allow for the engine’s study is briefly described. A step by step development of the general equations concerning mass, energy, entropy balances, and the Nusselt number for approximating the heat transfer coefficient is given and discussed. Results are shown through plotting numerical solutions of various points of interest. Lastly, a list of the program’s equations will be supplied in an appendix at the end of the paper.
Field Test of a Drag-Reducing Surfactant Additive in the Hydronic Cooling System of a Building: Phase 2 — Heat Transfer Control
Authors: Gasljevic K. , Hoyer K. , Matthys E. F. 
Published: January 2022

Abstract
A field test was conducted recently in the hydronic cooling system of a medium-size building. This test was the second phase of a study of the possible use of drag-reducing additives in hydronic systems for pumping power reduction. In the first phase of the field test we measured how much pumping power savings was achievable in this system, regardless of heat transfer reduction in the heat exchangers. We measured about 30% of pumping power savings. The recent second phase of the field test work had a different goal, namely to ascertain whether it is possible to control or eliminate the heat transfer reduction in the heat exchangers. This is an important issue because a loss in heat transfer capacity would lead to reduced chiller efficiency and therefore reduced net energy savings. We did indeed show in the second test that the use of an improved non-ionic surfactant did in fact allow us to control fully the heat transfer in the heat exchangers (both evaporator and cooling coils) by means of intentional temporary degradation of the drag-reducing properties of the solution. Even with full elimination of heat transfer reduction, we still achieved an overall 12% (limited by the small size and the configuration of the system) in pumping power savings, with no measurable effect on the heat transfer capacity of the evaporator or on the compressor power, even at full load. Furthermore, it was possible to eliminate the heat transfer reduction by degradation induced by components already existing in the system (pump and control valves). These issues and other aspects of the test strategy, implementation, and measurements are described.
Computer Simulation of the Thermal Performance of a Parallel/Countercurrent Flow Heat Exchanger for Patient Thermal Comfort in Medical Applications
Authors: Moujaes Samir , Oliver Dana 
Published: January 2022

Abstract
A computer simulation is proposed for a specialized heat exchanger used in the medical field which provides thermal comfort to potentially hypothermic patients whose bodies can provide a very limited amount of body heat. The model describes the thermal performance of the heat exchanger using a one-dimensional finite difference technique and solving a two-point boundary value problem to obtain the solution. It was found that the model predicts the thermal performance of the heat exchanger quantitatively when compared with the experimental data provided. The errors in predicting the difference between infusate inlet and outlet temperatures experimentally and theoretically were within 10% of experimental values and it is concluded that the program can be used for future design purposes.
Direct Numerical Simulation of a Coolant Jet in a Periodic Crossflow
Authors: Sharma Chirdeep , Acharya Sumanta 
Published: January 2022

Abstract
A Direct Numerical Simulation of a coolant jet injected normally into a periodic crossflow is presented. The physical situation simulated represents a periodic module in a coolant hole array with a heated crossflow. A collocated finite difference scheme is used which is fifth-order accurate spatially and second-order accurate temporally. The scheme is based on a fractional step approach and requires the solution of a pressure-Poisson equation. The simulations are obtained for a blowing ratio of 0.25 and a channel Reynolds number of 5600. The simulations reveal the dynamics of several large scale structures including the Counter-rotating Vortex Pair (CVP), the horse-shoe vortex, the shear layer vortex, the wall vortex and the wake vortex. The origins and the interactions of these vortical structures are identified and explored. Also presented are the turbulence statistics and how they relate to the flow structures.
A Study of Film Cooling Injection Geometries: Measured Flow and Thermal Fields With Lateral, Compound and In-Line Injection
Authors: Oke Rohit A. , Simon Terrence W. 
Published: January 2022

Abstract
Temperature field measurements taken with a traversing thermocouple are presented for compound angle injection with Φ = 45°. These are compared with data from lateral injection, Φ = 90°, and in-line injection, Φ = 0, cases. Near-wall values of these measurements, which are adiabatic effectiveness values, η, show the effect of Φ on film cooling performance. Complementary velocity field measurements, including streamwise and cross-stream velocity components, taken with triple-wire anemometry, are also presented for compound angle injection. These are compared with similar data for lateral and in-line injection cases presented in the literature. The main feature of the flow pattern with compound angle injection is the presence of an asymmetrical pair of counter-rotating vortices of unequal strength, the nature of which depends on the ratio of the momentum flux of the coolant and the mainstream and the injection angle, Φ. For compound angle injection, the stronger vortex appears to draw free stream fluid towards the wall, as with lateral injection, but to a lesser degree. Triple-sensor anemometry measurements also yield turbulent Reynolds stress distributions which allow discussion of anisotropy of turbulent transport. Eddy diffusion in cases of isotropic turbulence would follow the gradient diffusion model in which the shear stress vectors are perpendicular to the velocity gradients. Due to anisotropy, this is not the case over most of the flow field, however.
Running a Small Gas Turbine With and Without a Recuperator: Comparisons of Efficiency at Various Loads
Authors: Rosén Per , von Heiroth Paul , Lindquist Torbjörn 
Published: January 2022

Abstract
An advanced integrated humidification gas turbine process based on an Evaporative Gas Turbine cycle (EvGT), is being built at Lund University in Sweden. The pilot plant is based upon a new 600 kW gas turbine engine. The building of the complete cycle is done in steps, the first step is to run and record measurements from the simple open gas turbine cycle. The next step is to add a compact heat exchanger, a recuperator, to the process and repeat the measurements. This enables an evaluation of the performance of the recuperator in the gas turbine cycle. The result of this comparison is that the efficiency increase is lower than predicted in an earlier stage due to large heat losses of the inner cone extension of the combustion chamber and also because a large amount of compressed air is being used as dilution air just before the expansion take place in the expander.
Enhancing Small-Channel Convective Boiling Performance Using a Microporous Surface Coating
Authors: Ammerman C. N. , You S. M. 
Published: January 2022

Abstract
Performance characteristics are experimentally determined for enhanced convective boiling of FC-87 in horizontal, small-cross-sectional-area, single-channel heaters. Two different channels are tested which have square cross sections with side lengths of 2 and 0.5 mm, respectively. Each of the channels are 8 cm in length. The heated surface of each of the two channels is tested both with, and without, a microporous surface coating. Although few studies have been performed to quantify the effects of internal porous coatings on flow boiling, their application in this area is promising. The coating is shown to provide increases in both heat transfer coefficient and critical heat flux. Convective boiling curves are generated for mass fluxes from 500 to 5000 kg/m2s and for inlet subcooling levels ranging from 2 to 31°C.