bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experiments and Numerical Simulations of Swirling Fires due to 2 × 2 Flames in a Channel With a Single Corner Gap
Authors: Satoh Kohyu , Yang K. T. 
Published: January 2022

Abstract
Fire whirls are known to cause loss of lives and extreme property damages in large urban fires such as earthquake fires. This study focuses on the swirling flames generated by placing four identical symmetrical fires in a square channel with a single corner gap on one of the channel walls. The effects of the inter-fuel pan distance were examined experimentally and also numerically simulated by a field model. The numerical simulations show the existence of both the strong rotating flames and the vertical buoyant swirling flames, as also observed in the experiments. Furthermore, the simulations also show strong inflow from the channel top opening, resulting in extremely complex flow patterns inside the channel due to flow instabilities.
The Effect of Forcing on Scalar Transport in a Co-Axial Combustor Geometry
Authors: Chandra P. R. , Acharya S. , Sebastijanovic N. , Panigrahi P. 
Published: January 2022

Abstract
This paper investigates open-loop control of the mixing between an inner heated stream and an outer unhealed stream in coaxial combustor geometry. The inner and outer streams mimic the gaseous fuel and primary air stream in a gas turbine combustor. Of specific interest in this study is the behavior of the coherent structures, and the mixing in these coherent structures under the effect of controlled perturbation of the primary air stream. Two perturbation or forcing frequencies are studied: the preferred mode or fundamental frequency of the unforced flow which is measured to be 500 Hz, and the subharmonic frequency of 250 Hz. At each forcing frequency, three different forcing levels were examined. At the high-forcing level, the preferred mode forcing produces an increase in the spreading rate of both the inner and the outer jets. This is associated with increased entrainment into the coherent structures and increased mixing of the heated inner and unheated outer jet. With subharmonic forcing, a similar behavior is observed due primarily to the emergence of the fundamental as a dominant mode. At low-level forcing, the velocity profiles are only marginally affected, but the temperature profiles indicate a decrease in mixing. It is speculated that this is associated with increased coherence but without an associated increase in entrainment into the coherent structures.
A Numerical Study of Short Residence Time FCC Riser Flows With a New Flow/Kinetics Modeling Technique
Authors: Chang S. L. , Lottes S. A. , Petrick M. , Zhou C. Q. 
Published: January 2022

Abstract
Fluid Catalytic Cracking (FCC) technology is the most important process used by the refinery industry to convert crude oil to valuable lighter products such as gasoline. New and modified processes are constantly developed by refinery companies to improve their global competitiveness and meet more stringent environmental regulations. Short residence time FCC riser reactor is one of the advanced processes that the refining industry is actively pursuing because it can improve the yield selectivity and efficiency of an FCC unit. However, as the residence time becomes shorter, the impact of the mixing between catalyst and feed oil at the feed injection region on the product yield becomes more significant. Currently, most FCC computer models used by the refineries perform sophisticated kinetic calculations on simplified flow field and can not be used to evaluate the impact of fluid mixing on the performance of an FCC unit. Argonne National Laboratory (ANL) is developing a computational fluid dynamic (CFD) code ICRKFLO for FCC riser flow modeling. The code, employing hybrid hydrodynamic-chemical kinetic coupling techniques, is used to investigate the effect of operating and design conditions on the product yields of FCC riser reactors. Numerical calculations were made using the code to examine the impacts of the operating and design conditions on the product yields. The controlling parameters under investigation include the residence time, reaction temperature, and catalyst/oil ratio. This paper describes the CFD code, presents computational results, and discusses the effects of operating conditions on the performance of short residence time FCC riser reactors.
Effects of Surface Patterning in Thin Film Structures on the Thermal Radiative Properties During Rapid Thermal Processing
Authors: Tada Haruna , Abramson Alexis R. , Miaoulis Ioannis N. , Wong Peter Y. , Nieva Patricia , Zavracky Paul 
Published: January 2022

Abstract
Thermal processing is used in various stages of microelectronics fabrication. One of the heating processes may be rapid thermal processing (RTP), which involves high temperatures and heating rates, and short durations. Temperature control and uniformity within a few degrees is a requirement in RTP. Prediction, measurement, and control of wafer temperatures during RTP have been a challenge due to the highly non-linear radiative properties of the wafers. These properties are functions of temperature, wavelengths, doping level, surface patterns, and thin-film structures. A numerical model has been developed to determine the wafer radiative properties, taking into account bandgap, free carrier, and lattice absorption effects, as well as thin-film interference near the surface and partial transparency within the wafer thickness. Experimental measurements of spectral reflectivity of different pattern sizes were made for SiO2 stripes on Si wafer. Results indicate that the radiative properties of patterned wafers for pattern sizes down to 4 μm can be adequately predicted by the average reflectivity of Si and SiO2, weighted according to their relative areas. This was found to be true regardless of the diffractive effects seen visually. The numerically determined radiative properties were used in a model of radiantively heated patterned wafer to find the temperature distribution at steady-state. For the model wafer having 2550 Å SiO2 film on Si, with SiO2 and Si stripe patterns, the patterns created regions of high and low temperatures on the wafer, which can lead to significant thermal stresses and defects in the wafer.
An Investigation of Corrosion in Liquid-Metal Heat Pipes
Authors: Adkins Douglas R. , Rawlinson K. Scott , Andraka Charles E. , Showalter Steven K. , Moreno James B. , Moss Timothy A. , Cordiero Patricia G. 
Published: January 2022

Abstract
Research is underway to develop a 75-kW heat pipe to transfer solar energy from the focus of a parabolic dish concentrator to the heater tubes of a Stirling engine. The high flux levels and high total power level encountered in this application have made it necessary to use a high-performance wick structure with fibers on the order of 4 to 8 microns in diameter. This fine wick structure is highly susceptible to corrosion damage and plugging, as dissolved contaminants plate out on the evaporator surface. Normal operation of the heat pipe also tends to concentrate contaminants in localized areas of the evaporator surface where heat fluxes are the highest. Sandia National Laboratories is conducting a systematic study to identify procedures that reduce corrosion and contamination problems in liquid-metal heat pipes. A series of heat pipes are being tested to explore different options for cleaning heat-pipe systems. Models are being developed to help understand the overall importance of operating parameters on the life of heat-pipe systems. In this paper, we present our efforts to reduce corrosion damage.
Filtration of Aircraft Cabin Air Odors in 100% Relative Humidity, Low Temperature Conditions
Authors: Penrod Samuel L. , Unger Pete D. , Rohrbach Ronald P. , Bause Daniel E. , Xue Lixin , Dondero Russ A. 
Published: January 2022

Abstract
Aircraft cabin air is frequently contaminated by low concentration odor causing compounds. Activated carbon has a long history of effective application in gas stream treatment. However, little information is available on removing low concentration odor causing compounds in high humidity, cold air environments. Previous research suggests that high relative humidity would severely reduce the effectiveness of activated carbon filters. Operating conditions in aircraft low pressure water separators typically run at 100% relative humidity and 2°C.
Effluent or “breakthrough” curves at 5 ppmv toluene resulted in an adsorption capacity of 0.3 g toluene per gram media at 100% relative humidity compared to a 33% increase at less than 5% relative humidity, i.e. 0.4. Breakthrough analyses were performed at 5 to 40 ppmv toluene at face velocities of 50 to 180 m/min. These results indicate that carbon fiber based filter media hold the promise of effective odor control under conditions of high humidity and low temperature.
Analysis of Soil Heat Exchangers for Thermal Management of Outdoor Electronic Cabinets
Authors: Hegab Hisham E. , Zimmerman Eric B. , Colwell Gene T. 
Published: January 2022

Abstract
Telephone companies utilize densely packed electronics in outdoor metal cabinets for routing calls between customers. As a result of the increasing power densities of electronics, companies are looking for innovative methods of providing system level cooling such as using soil heat exchangers. Numerical simulation using a system of lumped thermal capacitances coupled to a soil finite element model is used to predict the transient thermal behavior of a cabinet. The cabinet model has been verified in previous studies by comparison with experimental measurements on a commercial telecommunications cabinet and is shown to predict temperature trends well. The effects of transient heat load, soil properties, and heat exchanger geometry are examined. Results reveal soil heat exchangers have the capability to provide the necessary cooling for relatively low power outdoor cabinets. However, the temperature of the soil surrounding the heat exchanger may increase daily if the number and spacing of pipes is not adequate to handle the desired heat dissipation load.
Study of Combined Method to Enhance Convective Heat Transfer
Authors: Chen Li 
Published: January 2022

Abstract
Experimental study of convective heat transfer in a tube with the combination of spring coil and flag-type inserts was performed to investigate the characteristics of heat transfer and flow drag. The test tube was a ϕ28 × 2 × 700 mm copper tube, and the working fluid was No.30 turbine oil. A piece of spring with the length of 100mm (wire diameter of 1.5mm and the pitch of 4mm) was set at the inlet of test tube, behind the spring 1–3 pieces of trapezoid shaped flag-type inserts made of stainless steel having a sweep angle of 76° length of 20mm width of 22mm and thickness of 0.3mm were hinged on a ϕ1.0 mm stainless steel vertical stick. It was shown that by means of the combined method heat transfer coefficient was greatly increased and the ratio of h/h0 was mostly higher than Δp/Δp0, also h/h0 increased in both the low and high Re regions. It was concluded that the advantages of these two components were combined and their disadvantages were reduced.
Heat Pipe Vapor Chamber Cold Plate Modeling, Fabrication and Testing
Authors: Zuo Z. Jon , Dussinger Peter M. 
Published: January 2022

Abstract
Heat pipe vapor chamber cold plates (HPVCCP) utilize highly efficient two-phase flow heat transfer to distribute concentrated heat to larger surface areas for effective dissipation. Because of the isothermal heat transfer characteristics, the HPVCCP is particularly suited for effective cooling of electronics. This paper presents the results of a recently completed study by Thermacore, Inc. on HPVCCP modeling, analysis, design, fabrication, processing, and testing. A two-dimensional numerical model was developed to calculate the liquid flow pressure distribution in the porous wick structure that is critical to determining the wick capillary limitation. A thermal network model was developed to calculate the temperature differences between the heating and cooling surfaces. Prototype, large size HPVCCP design, fabrication and testing issues are also discussed in the paper.
Natural Harmonic Locking of Sea–Gulf Systems and Effect of Their Artificial Instability on Mass Transfer
Authors: Kovinskaya Svetlana I. , Sofronov Valentin V. , Amromin Eduard L. 
Published: January 2022

Abstract
An analysis of water oscillation in the several sea-gulf systems on the base of shallow water theory and the actual bottom relief data was provided. Computation was carried out for each part of every system independently, and their amplitude responses were compared. The numerical analysis manifests that the sea oscillations have an influence on the gulf oscillations, and the inverse influence takes place too. Harmonic locking of oscillations in both part of the sea-gulf system is established. Tuning of the sea-gulf system oscillations is effected by the depth distribution only, but a correlation between gulf narrowness places and nodes of the main seiche modes is found. The amplitude responses and modes of three coupled sea systems are presented.
The influence of the large-scale engineering activity in the gulf of the Finland (a dam construction at its head near St.-Petersburg) on the gulf amplitude response are estimated. The results of the numerical analysis show the amplitude response changes as the dam effects. Besides, the nodes of the modes have displaced. Nowadays the dam effect introduces an artificial instability, but harmonic locking must lead to a restoration of the gulf amplitude response, with an according change of the bottom relief and of the shoreline as the long-term environmental effect of the dam construction. This change is a large-scale, long-term mass transfer in the environment caused by engineering.
A Discretization Approach for Conjugate Heat Transfer and Application to Turbomachinery Flows
Authors: Papanicolaou Elias L. , Giebert Dietmar , Koch Rainer , Schulz Achmed 
Published: January 2022

Abstract
A numerical procedure is presented to simulate conjugate heat transfer in generalized coordinates and used in some typical turbomachinery applications. The discretized equations at the solid-fluid interface are obtained using energy conservation principles and computational nodes are placed exactly on that interface, thus yielding the corresponding temperatures directly, without the need for inter- or extrapolation from neighboring nodes. The temperature field over both the fluid and the solid domains is computed implicitly, i.e., without iterating between the two. The computer code used for the computations is based on the finite-volume method and the SIMPLE algorithm along with various turbulence models. Both a version of the low-Reynolds-number k-ϵ model suitable for recirculating flows with heat transfer and the standard k-ϵ have been used, with suitable modifications.
The successful treatment of the boundary condition at the solid-fluid interface has been verified by comparing against analytical solutions for laminar, conjugate heat transfer over a flat plate of finite thickness. The agreement was found to be quite good, when temperature profiles were compared at various streamwise distances from the leading edge. Further applications have been sought in the field of turbomachinery and as the main test case, the turbulent flow and heat transfer in labyrinth seals has been selected. Two such configurations have been considered, a straight-through and a stepped labyrinth seal. Results were compared with measured data obtained for the same configurations and the agreement was found to be satisfactory. In addition, the applicability of the current method to a film-cooling problem and the merits of it are being demonstrated.
Prediction of Unsteady Wake-Passing Effects on Boundary Layer Development
Authors: Kim Kyoungjin , Crawford Michael E. 
Published: January 2022

Abstract
A boundary layer on the surface of a turbine blade can be significantly affected by the presence of periodic wake-passing from upstream blade rows, leading to a special form of transition mode from the high turbulence in the periodic wakes. In an effort to predict the evolution of wake-induced transition, time-resolved calculations were carried out using an unsteady two-dimensional boundary layer code and a newly developed transition model. The model is based on the theory of turbulent spot propagation and its subsequent growth. As a benchmark for the model, a single turbulent spot was simulated and compared with measurements. The results yielded the two-dimensional characteristics of the turbulent spot, as well as the becalmed region behind the spot. By imposing successive turbulent strips and freestream velocity defects in the time-space domain, the process of wake-induced transition was predicted for several test cases. The results showed good agreement on both the time-resolved and time-averaged measurements for the boundary layer quantities. In addition, predictions reproduced many details of the flow structure of wake-disturbed boundary layers and transition process.
A Performance Analysis Modeling for a Plate Heat Exchanger
Authors: Lee Jaeyong , Yoon Seokmann , Kim Chongbo , Jung Dongsoo , Seo Taebeom , Chun Wongee 
Published: January 2022

Abstract
Heat transfer characteristics and performance of a plate heat exchanger have been investigated through numerical modeling techniques. A 3-D finite volume technique has been utilized to solve the proposed numerical model. Flow passage turnings between upper and lower corrugated plates in the exchanger are assumed because two corrugated plates face each other with different channel angles where working fluid flows between two plates. The effects of flow channel angles and cross-sectional shapes of exchanger plates have been investigated to determine the optimum design parameters for the exchanger.
Within a plate heat exchanger, the flow passage is being determined due to flow interactions between the corrugated plates. Since the working fluid flows along the rather complicated flow path in actual situation, it is simplified that the flow from one direction changes its direction after colliding with the flow coming from the other direction due to the chevron angle of the plate. Various numbers of flow passage turnings are assumed for comparisons in order to obtain optimum performance conditions for the plate heat exchanger. The effects of cross-sectional shapes to the exchanger performance is also investigated.
Heat Transfer and Flow Friction Characteristics of a Compact Plate-Type Condenser
Authors: Cheng Lixin , Chen Tingkuan 
Published: January 2022

Abstract
Condensation heat transfer Experiments in a Model BRS08 plate-type condenser were conducted. The geometry parameters of the condenser are as follows: the gap between plates of vapor channel is 5.88mm and the average equivalent diameter is 10.16mm. The gap between plates of cooling channel is 3.87mm and the average equivalent diameter is 6.7mm; the available heat transfer area of a single plate is 0.802m2; the tested condenser consists of 4 vapor channels and 4 cooling water channels. The Reynolds number of cooling water was varied from 1400 to 16000. The vapor was condensed at an absolute pressure of 0.2Mpa. The experimental data were reduced to obtain correlations for heat transfer coefficient and friction factor.
Measurement of Flow Field in the Translational Region of a Twin-Screw Extruder: Effect of Material Behavior
Authors: Bakalis Serafim , Karwe Mukund V. 
Published: January 2022

Abstract
Laser Doppler anemometry (LDA) was used to measure velocity distributions in a table-top, co-rotating, self-wiping, twin-screw extruder having a Plexiglas barrel. Velocity measurements were made in the translational region of a 14 mm pitch forward conveying screw element. Axial (along the screw axis) and tangential (normal to the axis) velocity components were measured using a Newtonian (heavy corn syrup) and a pseudoplastic (CMC solution) fluid. The variation of velocity with screw rotation was similar for both fluids. The tangential velocity component for both fluids was higher closer to the screw flights and smaller in the middle of the screw channel. The axial velocity component was close to zero near the screw flights. Maximum values of the axial component were measured in the middle of the of the screw channel.
Measurement of Laser-Induced Shock Wave in Thin Nickel Foil
Authors: Song Kevin H. , Xu Xianfan 
Published: January 2022

Abstract
A polyvinylidene fluoride (PVDF) piezoelectric transducer is used for time-resolved measurements of shock waves generated by a KrF excimer laser irradiating a thin Nickel foil. Pressure loading due to both thermal expansion and surface evaporation is measured. The peak pressure of the shock wave increases with laser fluence, and the stress behind the shock reaches 390 bar at a laser fluence of 3.7 J/cm2. The mechanical coupling efficiency during laser-metal interaction is estimated for laser fluences between 0.72 and 3.7 J/cm2. The measurement results reveal prolonged pressure loading at the target surface after the termination of laser pulse, which is due to superheating of the surface layer during laser ablation.
Double Diffusive Velocity Measurement During the Solidification Process Using Particle Image Velocimetry
Authors: Wang S. Y. , Liu Y. Z. , Lin C. X. , Ebadian M. A. 
Published: January 2022

Abstract
This paper discusses the advanced technique, Particle Image Velocimetry (PIV), used to measure the velocity distribution of double diffusive convection of a binary mixture during the solidification process. The experiments were conducted using ammonium chloride solution in a rectangular enclosure. It was found that the double diffusive flow is stronger at the beginning of solidification and decays as solidification proceeds.
Axisymmetric Mixed Convection in the Annulus Between Vertical Concentric Cylinders With Axial Translation
Authors: Gagnon Daniel R. , Hill Roger W. , Ball Kenneth S. 
Published: January 2022

Abstract
Mixed convection in an air-filled annular enclosure between vertical concentric cylinders, which is driven by combined heating and axial translation of the inner cylinder, is simulated numerically. Both cylinders are assumed to be isothermal with an imposed temperature difference between them. The flow is assumed to be axisymmetric and the Boussinesq approximation is employed. The conservation equations for momentum and energy are solved using a spectral Chebyshev collocation technique utilizing a pressure Poisson influence matrix approach to maintain a solenoidal velocity field. The buoyancy driven flow observed at low Re is displaced by a forced convection cell that grows with increasing translational velocity until it fills the entire cavity at high Re. High heat transfer rates are observed for cases in which the air flow is dominated by either buoyancy or shear forces while low heat transfer rates result from flow driven by competing forces.