bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Influence of the Combustion Model on the Result of Turbulent Flames Numerical Simulations
Authors: Gherman Bogdan , Florean Florin Gabriel , Cârlănescu Cristian , Porumbel Ionuţ 
Published: July 2013

The paper is aimed at evaluating the impact of the combustion model on the accuracy of the results of the numerical simulations of turbulent reactive flows. For this, two numerical simulations of the well known Sandia Flame D case are carried out: a three-dimensional RANS integration of the Navier–Stokes equations using the Eddy Dissipation combustion Model (EDM), and a one-dimensional one, where simplified reaction–diffusion equations are numerically integrated over the radial direction, while the axial convection is modeled by empirical laws. The one-dimensional simulation, however, is based on a more physics related combustion model, the Linear Eddy Mixing model, which also controls the radial turbulent mixing and the large scale radial convection.
The results of the two numerical simulations are compared to experimental data in the literature, showing a significantly better accuracy of the Linear Eddy Mixing (LEM) numerical simulation.
Application of an Inter-Turbine Burner Using Core Driven Vitiated Air in a Gas Turbine Engine
Authors: Spytek Christopher J. 
Published: July 2013

An Inter-Turbine Burner (ITB) that is capable of increasing the thrust of a gas turbine engine with minimal effect on SFC has been developed. Gas turbine engines using multistage turbine sections have the inherent disadvantage of temperature loss through the turbine section. This occurs when each successive turbine stage extracts energy from the superheated mass airflow stream. The net result is limited energy potential due to the first stage turbine temperature limits. An Inter-Turbine Burner (ITB) is able to utilize constant temperature burning through the turbine section by adding burners between the turbine stages. The resultant engine is suited for missions requiring large amounts of constant or intermittent power extraction. The Spytek ITB incorporates a modified version of an Ultra-Compact Combustor (UCC) [1] (high-g burner) which was originally developed by the Air Force Research Laboratory in Dayton, Ohio.
The ITB has been incorporated into a gas turbine engine and has been successfully tested operating at a near constant temperature (NCT) cycle. The engine/ITB is specifically configured and packaged for high power density use. Temperature rises across the ITB (T6-7) were tested in ranges from 421K-588K with representative increases in power take-off noted. The burner, positioned directly upstream of the ITB turbine, operates with vitiated air taken directly from the core engine exhaust stream. The engine tested is a two spool turbo-jet (ITB shaft inclusive), in the 1334(N) class. The ITB is cross shaft linked to an axial compressor booster stage, attached to the engine inlet which super-charged the core engine.
The two major areas addressed in development were the ability to provide air into the primary burn zone of the ITB to sustain combustion and second, the ability to successfully entrain the combustion products from the ITB vortex chamber into the main air stream without causing undue restrictions or hot-streak problems which can affect the life of the ITB turbine. Flexibility in ITB testing is further enhanced through the use of two adjustable test features, 1) a variable flow splitter, capable of adjusting the amount of air diverted into the ITB combustor, and 2) a variable nozzle guide vane pack upstream of the ITB turbine. A proprietary entrainment system rapidly mixes the ITB combustor products with the main stream dilute flow products without any undo effects on the ITB turbine. The Mark#1 version of the ITB system exhibits power on demand increases of 16%–22%.
Numerical and Experimental Characterization of Low NOx Micromix Combustion Principle for Industrial Hydrogen Gas Turbine Applications
Authors: Funke H. H.-W. , Boerner S. , Keinz J. , Kusterer K. , Kroniger D. , Kitajima J. , Kazari M. , Horikawa A. 
Published: July 2013

The international effort to reduce the environmental impact of electricity generation, especially CO2-emissions requires considerations about alternative energy supply systems. An effective step towards low pollution power generation is the application of hydrogen as a possible alternative gas turbine fuel, if the hydrogen is produced by renewable energy sources, such as wind energy or biomass. The use of hydrogen and hydrogen rich gases as a fuel for industrial applications and power generation combined with the control of polluted emissions, especially NOx, is a major key driver in the design of future gas turbine combustors.
The micromix combustion principle allows a secure and low NOx combustion of hydrogen and air and achieves a significant reduction of NOx-emissions. The combustion principle is based on cross-flow mixing of air and gaseous pure hydrogen and burns in multiple miniaturized diffusion-type flames. For the characterization of the jet in cross-flow mixing process, the momentum flux ratio is used.
The paper presents an experimental analysis of the momentum flux ratio’s impact on flame anchoring and on the resultant formation of the NOx-emissions. Therefore several prototype test burner with different momentum flux ratios are tested under preheated atmospheric conditions. The investigation shows that the resultant positioning and anchoring of the micro flames highly influences the NOx-formation.
Besides the experimental investigations, numerical simulations have been performed by the application of a commercial CFD code. The cold flow simulation results show the mixing of the air and hydrogen after the injection, in particular in the Counter Rotating Vortices (CRV). Furthermore, the hydrogen jet interacts also with another vortex system resulting from a wake flow area behind the combustor geometry. Furthermore, reacting flow simulations have been performed by the application of a Hybrid Eddy Break-Up (EBU) combustion model. The combustion pressure has been varied from atmospheric conditions up to a pressure of 16 bar.
The experimental and numerical results highlight further potential of the micromix combustion principle for low NOx-combustion of hydrogen in industrial gas turbine applications.
Flammability of High Flash Point Liquid Fuels
Authors: Kay Peter J. , Crayford Andrew P. , Bowen Philip J. , Luxford James 
Published: July 2013

Current European Health and Safety Legislation was implemented to limit the chance of a serious explosion occurring in the workplace by highlighting potentially explosive atmospheres and ensuring that ignition sources are not present in these areas. Though hazardous area classification for gaseous and dust explosion hazards are well established, the same cannot be said for mists especially for high flash point liquids. However, a recent literature review of a range of (some fatal) incidents has shown that mist explosions are more common and the consequences more severe than previously anticipated. This work is, for example, applicable to the safe use of fuels and lubricants utilised in the gas turbine power generation and propulsion industries.
Previous studies of jet breakup regimes and idealised flammability studies have indicated that low pressure releases (<10 bar) of low volatility fuels may still give rise to combustion hazards. Impingement of accidental releases onto surfaces has been shown to exacerbate the potential hazard, or broaden the range of hazardous release conditions. However, although a theoretical case can be made for generating flammable environments under moderate release conditions, very little evidence has been provided to bridge the gap between ‘idealised’ studies and full-scale incidents. The aim of this first programme of work is to start the process of bridging this gap, leading to well founded safety guidance.
The test programme was conducted in a custom built spray chamber located in the Gas Turbine Research Centre (GTRC) of Cardiff University. The fuel was released at a predefined range of pressures of industrial relevance at atmospheric temperature. Igniters were positioned at three downstream locations and the continuous electrical discharge had an energy no greater than 4 mJ. Tests were conducted for ‘free sprays’ where the spray was directed along the length of the chamber, and for impinging sprays where the spray was aligned to impinge normal to a flat un-heated surface.
Gas oil (flash point > 61 °C) ignited as a free jet at a working pressure consistent with previous hypotheses. However, when the jet impinged on a solid surface then the resulting spray could be ignited at considerably lower delivery pressures. Although the impingement process is complex, the data will be discussed in light of contemporary models that predict initial jet/spray characteristics along with post-impingement characteristics. This paper presents a first step towards consolidating previous studies and improving future safety guidelines concerned with the risk posed by the flammability of accidental releases of pressurised high flashpoint fuels.
SU‐C‐103‐02: Localization Accuracy of a Novel Prone Breast Stereotactic Immobilization and Localization System
Authors: Mutaf Y , Yu C , Nichols E , Yi B , Prado K , D' Souza W , Regine W , Feigenberg S 
Published: July 2013

Purpose: The GammaPodTM stereotactic radiotherapy device incorporates a novel stereotactic immobilization system and a fiducial based localization frame for the breast. We present the localization accuracy achieved with this stereotactic system through an IRB approved prospective protocol. Methods: GammaPodTM target localization is achieved using a dual layered immobilization breast cup under a negative pressure which has a built‐in stereotactic frame. Patient CT scans were attained using a pivoted patient loader which automatically lowers the patient from a vertical position to a horizontal prone‐lying position. We then performed two CT scans 30 minutes apart, simulating the pre‐treatment imaging and treatment sessions. The patient is disconnected from the patient loader after the first scan, but the immobilization cup remains on the breast under 150 mmHg of negative pressure until the end of the second scan. Evaluation of target localization was carried out via previously implanted surgical clips (two to five) and superficially positioned markers (three to seven). Scans were performed with 1 mm CT slice thickness. Results: The first 9 patients' results are presented with a total of 25 patients expected. Two patients were excluded due to improper fitting of the breast cup and patient comfort; one patient was excluded due to loss of breast cup pressure between the two scans. In the remaining six patients, the spatial reproducibility of internal markers was found to be 1.2 ± 1.0 mm (range 0.3−3.7) in between the two scans while the external marker positions differed by 0.9 ± 0.9 mm (range 0.1−3.9). The intrinsic accuracy of the stereotactic localization system found to be 0.1 ± 0.1 mm. Conclusion: The GammaPodTM target localization system is a unique approach to breast immobilization employing stereotactic principles. Preliminary results of this study suggest that the overall localization uncertainty of this system is 2.8 mm (95% CL).C. Yu and W. Regine have financial interests in Xcision Medical Systems.
MO‐A‐500‐01: Future of Radiation Therapy Safety
Authors: Low D , Mutic S , Moore K 
Published: July 2013

Radiation therapy has undergone considerable changes in the past 20 years. The complexity of radiation therapy treatments has increased and there has been a corresponding response by medical physicists to adopt new techniques to assure that treatments are safely delivered. Quality assurance equipment manufacturers have developed devices that substantially aid the medical physicist in measurement and analysis of treatments. The radiation therapy delivery device manufacturers have also stepped in, modifying their traditional approach to device manufacturing and providing extensive equipment operation recording and to a lesser extent reporting. Treatment planning system vendors have also provided tools to aid medical physicists in developing critical treatment planning quality assurance processes. This symposium examines some of the current quality assurance technology research. It presents research into tools that will provide the treatment planner insights regarding the absolute quality of a specific treatment plan, methods for automatically and redundantly assuring that the proper patient is being treated in the proper location, in highly automated redundant checks of treatment plan delivery quality. Many of the techniques that will be described are looking for rare but potentially catastrophic errors, including human error, process errors, equipment failure, and software bugs. One of the challenges for designing and implementing these techniques includes the assumption that there will be little or no additional manpower available to implement and monitor these techniques. Therefore, most of the presented research will utilize autonomous functions and workflows that either involve no additional manpower efforts or improve the efficiency of existing efforts.Learning Objectives:1. Teach the challenges that medical physicists face in an ever increasingly complex medicine.2. Show examples of novel quality assurance technologies that improve the stability and quality of treatment plans.3. Show examples of autonomous software and quality assurance workflows that monitors the treatment planning and delivery process to identify errors.4. Show examples of techniques that expand the ability of medical physicists to provide expert advice.
MO‐A‐103‐01: Nuclear Medicine: Regulatory Guidelines and Computational Methods for Safe Release of Radioactive Patients
Authors: Wendt R , Mourtada F 
Published: July 2013

Radiation therapy using radioactive materials within the patient, i.e., permanently implanted sealed brachytherapy seeds and unsealed targeted radiopharmaceuticals, is routinely used to treat cancer patients. Radioactive patients may safely be released from radiation safety restrictions when the most exposed person is unlikely to receive more than 5 mSv (500 mrem) according to the United States Nuclear Regulatory Commission. NUREG 1556 Volume 9 Appendix U Revision 2 presents regulatory guidance that may be used to assure compliance with this limit. This risk‐based approach is a big step forward from the prior activity‐based release criteria. This session will introduce commonly used radiation therapies using internal sealed and unsealed radioactive sources and discuss the criteria and computational methods for the safe release of radioactive patients. Essential components of NRC Part 35 Medical Use of Byproduct Material will also be presented.Learning Objectives:1. Introduce commonly used radiation therapies involving internally administered radioactive materials2. Present NRC guidelines and perform the calculations in the regulatory guidance documents3. Understand the implications and limitation of the release criteria calculation
MO‐A‐108‐01: The Impact of Intensity Modulated Proton Therapy On Proton Therapy?
Authors: Chen R , Bortfeld T , Kruse J , Zhang X , Chang J 
Published: July 2013

One of the major controversies surrounding proton therapy is that despite the high cost of proton therapy relative to conventional x‐ray radiotherapy, the clinical benefit of proton therapy has not been clearly demonstrated in the literature. The majority of clinical studies comparing proton and photon therapy have compared passive scattering proton therapy (PSPT) with intensity‐modulated radiation therapy (IMRT). However, the delivery of proton therapy, while predominantly in the form of PSPT, is likely to be superseded by intensity modulated proton therapy (IMPT). Improvement in dose distribution by IMPT in a representative series of patients compared to IMRT has been reported. It appears that IMPT will have the opportunity to justify adopting the proton therapy in the routine care for majority disease.This session will begin with a short introduction explaining the current state of the art for IMPT. This introduction will be followed by four presentations. The first presentation will cover the efficacy of proton therapy for prostate cancer from a clinician's point of view. The second presentation will provide more detail on the current state of the art for proton therapy, introduce future research directions for IMPT technology, and address the impact of the research on proton therapy. The third presentation will cover the clinical and operational reasoning behind an all‐scanning‐beam facility and the expertise needed to build such a facility. In the fourth presentation, a physicist and a physician will present their center's experience with implementing IMPT techniques for lung, head and neck, and central nervous system tumors and present relevant clinical protocols and data.Learning Objectives:1. Describe the current machine delivery systems and treatment planning, quality assurance, and dose verification techniques for IMPT.2. Explain the clinical efficacy and cost‐effectiveness of proton therapy.3. Differentiate the capabilities of IMPT from those of PSPT and IMRT and explain how the unique capabilities of IMPT improve the clinical efficacy and cost‐effectiveness of proton therapy.4. Provide examples of working clinical protocols, workflow, and quality assurance procedures for the use of IMPT in routine patient care.
MO‐A‐WAB‐01: MRI‐Guided Radiation Therapy
Authors: Jaffray D , Mutic S , Fallone B , Raaymakers B 
Published: July 2013

The concept of integrating a magnetic resonance imaging (MRI) scanner with a therapy radiation source, either a therapy linear accelerator (linac) or 60 Co, emerged as a feasible novel approach for MRI‐guided radiation therapy (i.e. MRIgRT or MRgRT) in recent years. The main motivation for the technological development of such radiotherapy systems is to provide state of the art MR imaging inside the treatment room to guide the treatment delivery. MRI offers the capability to visualize soft‐tissue as well as to perform physiological assessment of healthy and tumor tissues. The aim of MRIgRT is to facilitate adaptive radiotherapy by using on demand MRI data to update and personalize patient treatments.The MRI‐linac/ 60 Co system integration is a challenging task due to the intrinsic default incompatibility between the sub‐components. Multiple interdependent issues need to be resolved in order to achieve the optimal operation of the MRI scanner and the radiation source(s) such as: a) radiofrequency (RF) interference, b) magnetic field coupling, c) perturbation of the dose deposited in tissue due to the presence of an external magnetic field, and d) escalation of patient skin dose. This translates into solving a complex optimization problem which drives the overall system architecture. The session will provide an overview of the MRI‐guided radiation therapy systems. The speakers will present the specifics of their proposed designs and the latest technological developments (hardware and software). They will also discuss key aspects related to the clinical implementation of their systems such as safety, applications, workflows, quality control, staffing models for supporting the infrastructure, and preliminary data.Learning Objectives:1. Understand the main concepts of MRI‐guided radiation therapy;2. Understand the issues and proposed solutions related to the integration of MRI‐guided radiotherapy systems;3. Understand the advantages and limitations of MRI‐guided radiotherapy systems.
MO‐A‐141‐02: Session In Memory of Fearghus O't Foghludha – Virtual Tools for Validation of X‐Ray Breast Imaging Systems
Authors: Bakic P , Myers K , Reiser I , Kiarashi N , Zeng R 
Published: July 2013

Given the large number of design parameters available to an x‐ray imaging system innovator (x‐ray spectrum, number of projection angles, angular range, dose and reconstruction algorithm, to name a few), simulation methods offer significant advantages over clinical studies for evaluation of the alternatives in terms of reproducibility, reduced radiation exposures of patients and volunteers, a known reference standard, and the capability for studying patient and disease subpopulations through appropriate choice of breast and patient model parameters. For these reasons, the emergent use of Virtual Clinical Trials for preclinical assessment of x‐ray breast imaging methods has introduced a demand to optimize protocols for simulation studies. The protocols should comprise of specifications for breast phantoms, the simulated data representation, methods for incorporating phantoms into a model for the imaging process, and appropriate statistical assessment methods applied to the resulting simulated images. This symposium explores simulation methods for evaluation of novel x‐ray breast imaging systems — the subject of recently established AAPM taskgroup TG234. The focus is on the various approaches of developing software anthropomorphic phantoms and their use in the statistical assessment of novel imaging systems along with computational models for the x‐ray image formation process. The symposium will review and discuss the state of the science of Virtual Clinical Trials for novel x‐ray breast imaging systems. Presentations will discuss real‐time simulation of breast anatomy, simulation of small‐scale tissue properties, generation of breast phantoms based upon clinical datasets, and task‐based evaluation of x‐ray breast imaging systems using software phantoms.Learning Objectives:1. Review current approaches for simulation of breast phantoms for x‐ray imaging, along with their strengths and limitations;2. Understand the validation of software phantoms using object and image statistics;3. Review methods for statistical and task‐based image quality assessment and discuss their applications in x‐ray breast imaging systems;4. Illustrate methods for performing virtual clinical trials of emerging 3D x‐ray breast imaging systems.P.R.B. is a PI on NSF grant IIS0916690 and co‐investigator on NIH R01 CA154444, NIH R21 CA155906‐01A1, and DoD HBCU PTA BC083639, and is also involved in research collaboration with Barco, Inc. and Hologic, Inc.N.K. is funded by NIH R01 CA134658 and R01 CA11243, and is involved in resaerch collaboration with Siement Medical Solution.
MO‐A‐144‐02: Workshop
Authors: Sammet S , Lu Z 
Published: July 2013

List of the companies who have promised to support the workshop:1. Philips MR guided HIFU. (Contact person: Lizette Warner, Ph.D., 595 Miner Rd Cleveland, OH 44143, Tel: (440) 483‐3000, e‐mail: Lizette Warner@philips.com)2. InSightec Ltd. ( Contact person: James E. Davis, Chief Executive Officer, 10501 W Research Dr., Ste G100, Milwaukee, WI 53226, Tel: (262)613‐4212, email: jamesd:jamesd@Insightec.com@Insightec.com :jamesd@Insightec.com)3. US HIFU, LLC (Contact: Naren Sanghvi, Chief Scientific Officer, 4000 Pendleton Way, Indianapolis, IN 46226. Email: narensanghvi :narensanghvi@ushifu.com@ushifu.com :narensanghvi@ushifu.com, Phone: 317‐352‐5812.)4. Alpinion Medical Systems (Contact person: Yuchi Chu, Director, Suite 229, 10604 NE 38th Place, Kirkland, WA 98033, tel: (425) 949‐4907, email: ychu :ychu@alpinionus.com@alpinionus.com :ychu@alpinionus.com)5. FUS Instruments Inc. (Contact person: Daniel Pajek, VP, Operations, (647)238‐7146, email: dpajek :dpajek@fusinstruments.com@fusinstruments.com :dpajek@fusinstruments.com>)