Spray and High-Pressure Flow Computations in the National Combustion Code (NCC) Improved

Sprays occur in a wide variety of industrial and power applications and in materials processing. A liquid spray is a two-phase flow with a gas as the continuous phase and a liquid as the dispersed phase in the form of droplets or ligaments. The interactions between the two phases--which are coupled through exchanges of mass, momentum, and energy--can occur in different ways at disparate time and length scales involving various thermal, mass, and fluid dynamic factors. An understanding of the flow, combustion, and thermal properties of a rapidly vaporizing spray requires careful modeling of the ratecontrolling processes associated with turbulent transport, mixing, chemical kinetics, evaporation, and spreading rates of the spray, among many other factors. With the aim of developing an efficient solution procedure for use in multidimensional combustor modeling, researchers at the NASA Glenn Research Center have advanced the state-of-the-art in spray computations in several important ways

ASPECT-BASE PROXY-ORIENTED INFORMATION SAVING AND DISTANT DATA RELIABILITY VERIFICATION IN CLOUD

This paper is dependent on the study outcomes of proxy cryptography, identity-based public key cryptography and remote data integrity checking in public places cloud. In public places cloud, this paper concentrates on the identity-based proxy-oriented data uploading and remote data integrity checking. By utilizing identity-based public key cryptology, our suggested ID-PUIC protocol is efficient because the certificate management is eliminated. ID-PUIC is really a novel proxy-oriented data uploading and remote data integrity checking model in public places cloud. Using the public cloud platform, the customers are relieved from the burden for storage management, universal data access with independent geographical locations, etc. Throughout analysis, the manager is going to be limited to connect to the network to be able to guard against collusion. But, the manager’s legal business will go on throughout analysis. We provide the formal system model and security model for ID-PUIC protocol. Then, in line with the bilinear pairings, we designed the very first concrete ID-PUIC protocol. Within the random oracle model, our designed ID-PUIC protocol is provably secure. However, the suggested ID-PUIC protocol may also realize private remote data integrity checking, delegated remote data integrity checking and public remote data integrity checking in line with the original client’s authorization

LSPRAY: Lagrangian Spray Solver for Applications With Parallel Computing and Unstructured Gas-Phase Flow Solvers

Sprays occur in a wide variety of industrial and power applications and in the processing of materials. A liquid spray is a phase flow with a gas as the continuous phase and a liquid as the dispersed phase (in the form of droplets or ligaments). Interactions between the two phases, which are coupled through exchanges of mass, momentum, and energy, can occur in different ways at different times and locations involving various thermal, mass, and fluid dynamic factors. An understanding of the flow, combustion, and thermal properties of a rapidly vaporizing spray requires careful modeling of the rate-controlling processes associated with the spray's turbulent transport, mixing, chemical kinetics, evaporation, and spreading rates, as well as other phenomena. In an attempt to advance the state-of-the-art in multidimensional numerical methods, we at the NASA Lewis Research Center extended our previous work on sprays to unstructured grids and parallel computing. LSPRAY, which was developed by M.S. Raju of Nyma, Inc., is designed to be massively parallel and could easily be coupled with any existing gas-phase flow and/or Monte Carlo probability density function (PDF) solver. The LSPRAY solver accommodates the use of an unstructured mesh with mixed triangular, quadrilateral, and/or tetrahedral elements in the gas-phase solvers. It is used specifically for fuel sprays within gas turbine combustors, but it has many other uses. The spray model used in LSPRAY provided favorable results when applied to stratified-charge rotary combustion (Wankel) engines and several other confined and unconfined spray flames. The source code will be available with the National Combustion Code (NCC) as a complete package

The Blast Waves From Unconfined Axisymmetric Vapour-Cloud Explosions

277 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1982.This dissertation presents a systematic study of the blast waves produced by axisymmetric detonation waves and constant velocity as well as accelerating deflagration waves propagating through homogeneous axisymmetric clouds whose energy density approximate that of a typical hydrocarbon-air mixture. The behavior of the blast wave was studied in a compressible medium surrounding a flammable mixture during and after the propagation of a heat addition wave which models the detonation or deflagration process. In this study the non-steady, two-dimensional fluid dynamic equations of motion were integrated using Godunov's computational scheme subject to appropriate boundary conditions. The actual combustion process was replaced by a simple heat-addition working fluid model developed by Strehlow and coworkers. The results yielded the fluid dynamic and thermodynamic fields associated with the propagation of the blast wave. Particular attention was concentrated in determining the blast parameters, i.e. peak overpressure and impluse, using the numerical calculations for various cloud geometries and flame velocities. A general acoustic monopole source theory was also used in determining the peak overpressure and impulse produced by the low velocity deflagration of non-spherical axisymmetric clouds. Reasonable agreement was found between the values obtained from the numerical calculations and the linear-acoustic theory for low velocity flames.The results indicate that deflagrative combustion of extended clouds is very ineffective in producing damaging blast waves when compared with the spherical blast wave generated by an equivalent cloud of identical fuel-air mixture. On the contrary, a high pressure burst and detonative combustion of axisymmetric clouds exhibit pronounced directional blast effects with very high overpressures near the source volume. From the results of this study, it appears likely that large flame accelerations and velocities close to detonation are needed for the combustion of an extended cloud to produce a damaging blast wave.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Preliminary Soot Computations Based on a Model Aircraft Combustor With OpenNCC

In a preliminary effort to extend our current capabilities used in the design & testing of aero-engine combustors to particulate emissions, we incorporated several existing 2- equation soot models into the Open National Combustion Code (OpenNCC). The paper presents results from a validation study based on a well-characterized, swirl-stabilized, turbulent sooting flame generated by a model aero-engine combustor developed at DLR, Germany. The calculations are based on a Reynolds-Averaged Navier Stokes (RANS) simulation with standard k-e turbulence model & a finite-rate chemical kinetic mechanism. A separate transport equation is solved for all individual species involved in ethylene/air combustion. The predicted velocity and temperature are mostly in good agreement with the measured data and reasonable agreement was found for soot. While the calculated SVF (Soot Volume Fraction) behavior is similar to some other predicted results reported in literature, the measured soot lasts farther downstream than the calculated soot indicating a need for further improvement in the soot models employed

A Cross-Layer, Anomaly-Based IDS for WSN and MANET

Intrusion detection system (IDS) design for mobile adhoc networks (MANET) is a crucial component for maintaining the integrity of the network. The need for rapid deployment of IDS capability with minimal data availability for training and testing is an important requirement of such systems, especially for MANETs deployed in highly dynamic scenarios, such as battlefields. This work proposes a two-level detection scheme for detecting malicious nodes in MANETs. The first level deploys dedicated sniffers working in promiscuous mode. Each sniffer utilizes a decision-tree-based classifier that generates quantities which we refer to as correctly classified instances (CCIs) every reporting time. In the second level, the CCIs are sent to an algorithmically run supernode that calculates quantities, which we refer to as the accumulated measure of fluctuation (AMoF) of the received CCIs for each node under test (NUT). A key concept that is used in this work is that the variability of the smaller size population which represents the number of malicious nodes in the network is greater than the variance of the larger size population which represents the number of normal nodes in the network. A linear regression process is then performed in parallel with the calculation of the AMoF for fitting purposes and to set a proper threshold based on the slope of the fitted lines. As a result, the malicious nodes are efficiently and effectively separated from the normal nodes. The proposed scheme is tested for various node velocities and power levels and shows promising detection performance even at low-power levels. The results presented also apply to wireless sensor networks (WSN) and represent a novel IDS scheme for such networks

Estimation of serum β2-microglobulin in potentially malignant disorders and squamous cell carcinoma of the oral cavity: A clinicopathological study

Background: Tumor markers are substances, which quantitatively changes in serum, during the tumor development, one such tumor marker is serum β2-microglobulin (β2-m). The aim of this study was to establish the role of β2-m as a biochemical parameter for diagnosis and prognosis of oral carcinoma by estimation of serum β2-m levels in potentially malignant lesions, conditions, and oral squamous cell carcinoma. Materials and Methods: The study was carried out on 48 subjects (16 control, 8 oral submucous fibrosis, 8 oral leukoplakia, and 16 oral squamous cell carcinoma patients of different stages), conducted at department of Oral Medicine, Kothiwal Dental College, Moradabad, India. Under aseptic precautions, 5 ml venous blood was drawn and serum was separated. Estimation of β2-m level in serum was carried out by enzyme linked immunosorbent assay. The data were analyzed by using the statistical package for social sciences (SPSS 17.0) software. Cases and controls were tested for statistical significance with one-way ANOVA with post-hoc Tukey′s HSD. Values of P < 0.05 were considered significant. Results: The mean serum β2-m level in the control group was 1.173 ± 0.059, in potentially malignant lesions/conditions group was 1.688 ± 0.137 and in oral squamous cell carcinoma group was 2.835 ± 0.0313. This progressive increase in serum β2-m level was found to be highly significant (P value < 0.001). Results of Receiver operating characteristic analysis showed β2-m as a 100% sensitive and specific biomarker for oral squamous cell carcinoma. Conclusion: The present study establishes β2-m as a specific biological tumor marker for diagnostic and prognostic evaluation of oral squamous cell carcinoma

Ultrasonography with color Doppler and power Doppler in the diagnosis of periapical lesions

Aim: To evaluate the efficacy of ultrasonography (USG) with color Doppler and power Doppler applications over conventional radiography in the diagnosis of periapical lesions. Materials and Methods: Thirty patients having inflammatory periapical lesions of the maxillary or mandibular anterior teeth and requiring endodontic surgery were selected for inclusion in this study. All patients consented to participate in the study. We used conventional periapical radiographs as well as USG with color Doppler and power Doppler for the diagnosis of these lesions. Their diagnostic performances were compared against histopathologic examination. All data were compared and statistically analyzed. Results: USG examination with color Doppler and power Doppler identified 29 (19 cysts and 10 granulomas) of 30 periapical lesions accurately, with a sensitivity of 100% for cysts and 90.91% for granulomas and a specificity of 90.91% for cysts and 100% for granulomas. In comparison, conventional intraoral radiography identified only 21 lesions (sensitivity of 78.9% for cysts and 45.4% for granulomas and specificity of 45.4% for cysts and 78.9% for granulomas). There was definite correlation between the echotexture of the lesions and the histopathological features except in one case. Conclusions: USG imaging with color Doppler and power Doppler is superior to conventional intraoral radiographic methods for diagnosing the nature of periapical lesions in the anterior jaws. This study reveals the potential of USG examination in the study of other jaw lesions