ABSTRACT Transportation, separation and drying of agricultural products harvested in nature, such as sugarcane without burning and grains (soybeans and others), requires the proper operation of industrial devices, because will be present besides products such as straw, earth and boulders. These devices must be capable of separating the various component parts of the raw materials of agricultural production to storage and processing. Such separation processes are fully understood and executed with detailed knowledge of the flow fields, indicating the intensity and direction of the velocity vectors. These parameters can be obtained with the use of a numerical-computational model of equations of non-viscous fluid mechanics. To do this, you can use the Euler equations 2-D to represent how develops the flow within ducts and industrial devices, making it possible to meet the local and global behavior in various parts, from the entrance of the agricultural product out of this. This allows you to check the need for constructive adequacy scale issues or subsidize the improvement of the process of separation of the agricultural automatically. Industrial applications include transportation, separation and drying (heat transfer), grain, sugar cane and other agricultural products.

RESUMEN Transporte, separación y secado de productos agrícolas cosechados en la naturaleza, como la caña de azúcar sin quemar y granos (soja y otros), requiere el correcto funcionamiento de dispositivos industriales, porque estarán presentes además de los productos como paja, tierra y rocas. Estos dispositivos deben ser capaces de separar los diversos componentes de la materia prima de la producción agrícola para almacenamiento y procesamiento. Estos procesos de separación son completamente entendidos y ejecutados con conocimiento detallado de los campos de flujo, que indica la intensidad y la dirección de los vectores de velocidad. Estos parámetros pueden obtenerse con el uso de un modelo numérico computacional de las ecuaciones de la mecánica de fluidos no viscosos. Para ello, pueden utilizar las ecuaciones de Euler 2-D para representar cómo se desarrolla el flujo dentro de conductos y dispositivos industriales, lo que es posible conocer el comportamiento local y global en varias partes, desde la entrada de los productos agrícolas de esta. Esto le permite comprobar la necesidad de adecuaciones constructivas problemas de escala o subvencionar la mejora del proceso de separación del producto agrícolo de forma automatizada. Aplicaciones industriales incluyen transporte, separación y secado (transferencia de calor), grano, caña de azúcar y otros productos agrícolas.

Abstract: The present paper investigates the high-order spectral finite volume method with emphasis on applicability aspects for compressible flows. The intent is to improve the understanding and implementation of numerical techniques related to high-order unstructured grid schemes. In that regard, a hierarchical moment limiter and high-order mesh capability are developed for a 2-dimensional Euler spectral finite volume solver. The limiter formulation and geometry interpreter for high-order mesh generation are new contributions for the spectral finite volume method. Literature test cases are evaluated to assess the interaction of curved mesh, limiter and spatial reconstruction features of the spectral finite volume scheme. An order-of-accuracy study is presented along with steady and unsteady problems with strong shock waves and other discontinuities typical of compressible flows. Moreover, second, third and fourth-order spatial resolution analyses are explored and the spectral finite volume results are compared with those from different numerical methods.

ABSTRACT: It is performed and presented an experimental and numerical investigation over the flow patterns around the fore-body section of a microsatellite launch vehicle in development at Instituto de Aeronáutica e Espaço. The experimental investigation with a VLM-1 model in 1:50 scale is carried out at the Brazilian Pilot Transonic Wind Tunnel, located in the Aerodynamics Division of the mentioned Institute, using the classical schlieren flow visualization technique. Schlieren images are obtained for nominal Mach number varying from 0.9 to 1.01. Numerical simulation using Stanford's SU2 code is conducted together with the experimental investigation in order to improve the understanding of the complex physical phenomena associated with the experimental results of this particular regime. The combination of the 2 techniques allowed the assessment of some important aspects on the flow field around the vehicle in the conditions considered in this study, such as shock wave/boundary-layer interaction. The numerical simulation is also very important, allowing the quantification of some important parameters and confirming the shock wave formation patterns observed in the simulation when compared with the schlieren images. A good agreement regarding the position of the shock wave, when compared with the schlieren images, with a maximum error of about 6%, is observed over the VLM model.

RESUMO O presente estudo tem por objetivo relatar dois casos suspeitos que apresentam bow tie assimétrico e encurvamento inferior nas avaliações topográficas de reflexão (Placido) e projeção (Scheimpflug). A tomografia de córnea e segmento anterior com o sistema Scheimpflug (Oculus Pentacam HR, Wetzlar, Alemanha)® mostrou no primeiro caso, a ceratometria máxima (Kmax) de 43,2 D e o valor D no Belin/Ambrósio Enhanced Ectasia Display (BAD-D) de 1,76 no olho estudado (OD). O olho contralateral apresentava BAD-D de 6,59 e achados clínicos compatíveis com ceratocone (KC) grau 2. O segundo caso apresentava Kmax de 45,3 D e BAD-D de 0,76 em OD e 1,01 em OS. Este paciente havia interrompido o uso de lentes de contato gelatinosas 1 dia antes do exame. A avaliação tomográfica avançada nos permitiu distinguir ceratocone leve ou subclínico de warpage induzido por lentes de contato, enquanto resultados semelhantes foram observados em mapas de curvatura anterior.

ABSTRACT We report two cases of suspicious asymmetric bow tie and inferior steepening on topographic evaluations with reflection (Placido) and projection (Scheimpflug). Rotating Scheimpflug corneal and anterior segment tomography (Oculus Pentacam HR, Wetzlar, Germany)® was performed in the first case, with a maximal keratometric value (Kmax) of 43.2 D and an overall deviation value from the Belin/Ambrósio Enhanced Ectasia Display (BAD-D) of 1.76, which was observed in the study eye (OD). BAD-D was 6.59 in the fellow eye, which had clinical findings that were consistent with keratoconus stage 2. The second case presented with a Kmax of 45.3 D and BAD-D of 0.76 in OD and 1.01 in OS. This patient had discontinued wearing soft contact lens less than 1 day prior to examination. Corneal tomographic data enabled us to distinguish mild or forme fruste keratoconus from contact lens-induced corneal warpage, and similar findings were observed on curvature maps.

ABSTRACT: The atmospheric hypersonic flight of sub-orbital and space vehicles generates aerodynamic heating and high wall heat fluxes, inducing high temperatures on the vehicle's structures and affecting their mechanical behavior, besides degrading the operation of board equipment. Furthermore, since payload preservation is always mandatory, the use of efficient Thermal Protection Systems (TPS) is a key-requirement for any spacecraft design. As an outcome, designing the TPS is a critical aspect of any rocket development program, since an undersized system may result in catastrophic failure, and an oversized one implies increased mass and cost. Sub-orbital platforms are a low-cost alternative for microgravity research. A sub-orbital platform (SARA) is being developed by Instituto de Aeronáutica e Espaço (IAE) for such an application, and its current design uses a conventional layer of cork as TPS to protect its lateral surface, with the trade-off of large mass. Alternatively, a Thermally Integrated Structural Sandwich Core (TISSC), which consists of a structural sandwich panel in a three-layer plate with two face sheets and the core, presents advantages such as lightweight, low maintenance, insulation as well as load bearing capabilities, and low life-cycle cost. In this work, a TISSC is proposed to replace SARA's current TPS. The main contribution of the presented methodology is to couple the aerodynamic heating, heat transfer in porous insulation and thermo-structural analyses of the proposed configuration in order to evaluate the TISSC TPS performance. The results are compared with those obtained for the current SARA TPS design, showing improvements in thermal insulation and structural strength, as well as a remarkable mass reduction.

ABSTRACT: The work is a study of conservation on linearization techniques of time-marching schemes for the unstructured finite volume Reynolds-averaged Navier-Stokes formulation. The solver used in this work calculates the numerical flux applying an upwind discretization based on the flux vector splitting scheme. This numerical treatment results in a very large sparse linear system. The direct solution of this full implicit linear system is very expensive and, in most cases, impractical. There are several numerical approaches which are commonly used by the scientific community to treat sparse linear systems, and the point-implicit integration was selected in the present case. However, numerical approaches to solve implicit linear systems can be non-conservative in time, even for formulations which are conservative by construction, as the finite volume techniques. Moreover, there are physical problems which strongly demand conservative schemes in order to achieve the correct numerical solution. The work presents results of numerical simulations to evaluate the conservation of implicit and explicit time-marching methods and discusses numerical requirements that can help avoiding such non-conservation issues.

Justificativa e objetivo: avaliar as repercussões clínicas, hemodinâmicas, gasométricas e metabólicas das altas pressões transitórias do pneumoperitônio por curto período de tempo que garantem maior segurança para a introdução do primeiro trocarte. Métodos: foram estudados 67 pacientes submetidos a procedimentos videolaparoscópicos e aleatoriamente distribuídos em grupo P12: n = 30 (pressão intraperitoneal [PIP] de 12 mmHg) e grupo P20: n = 37 (PIP de 20 mmHg). Foram avaliados a pressão arterial média (PAM), por cateterismo da artéria radial; e, mediante gasometria, o pH, a pressão parcial de oxigênio arterial (PaO2), a pressão parcial de CO2 arterial (PaCO2), o bicarbonato (HCO3) e a reserva alcalina (BE). Esses parâmetros foram avaliados em ambos os grupos no tempo zero, antes do pneumoperitônio (TP0); no tempo um (TP1), quando a PIP atinge 12 mmHg em ambos os grupos; no tempo dois (TP2), após cinco minutos com PIP de 12 mmHg em P12 e após cinco minutos com PIP de 20 mmHg em P20; e no tempo três (TP3), após 10 minutos com PIP de 12 mmHg em P12 e com PIP retornada de 20 mmHg para 12 mmHg, contados 10 minutos após TP1 em P20. Os valores diferentes dos considerados normais para os parâmetros aquilatados ou o surgimento de fenômenos orgânicos atípicos foram considerados alteracões clínicas. Resultados: ocorreram diferenças estatísticas significantes no grupo P20 na PAM, no pH, no HCO3 e na BE, mas dentro dos limites da normalidade. Não foram evidenciadas alterações clínicas e patológicas. Conclusões: pressão intra-abdominal alta e transitória causa alterações da PAM, do pH, do HCO3 e da BE sem que haja repercussão clínica no paciente.

Background and objective: to evaluate the clinical, hemodynamic, gas analysis and metabolic repercussions of high transient pressures of pneumoperitoneum for a short period of time to ensure greater security for introduction of the first trocar. Methods: sixty-seven patients undergoing laparoscopic procedures were studied and randomly distributed in P12 group: n = 30 (intraperitoneal pressure [IPP] 12 mmHg) and P20 group: n = 37 (IPP of 20 mmHg). Mean arterial pressure (MAP) was evaluated by catheterization of the radial artery; and through gas analysis, pH, partial pressure of oxygen (PaO2), partial pressure of CO2 (PaCO2), bicarbonate (HCO3) and alkalinity (BE) were evaluated. These parameters were measured in both groups at time zero before pneumoperitoneum (TP0); at time 1 (TP1) when IPP reaches 12mmHg in both groups; at time 2 (TP2) after five min with IPP = 12mmHg in P12 and after 5 min with IPP = 20mmHg at P20; and at time 3 (TP3) after 10 min with IPP = 12mmHg in P12 and with return of IPP from 20 to 12mmHg, starting 10min after TP1 in P20. Different values from those considered normal for all parameters assessed, or the appearance of atypical organic phenomena, were considered as clinical changes. Results: there were statistically significant differences in P20 group in MAP, pH, HCO3 and BE, but within normal limits. No clinical and pathological changes were observed. Conclusions: high and transient intra-abdominal pressure causes changes in MAP, pH, HCO3 and BE, but without any clinical impact on the patient.

Justificación y objetivo: evaluar las repercusiones clínicas, hemodinámicas, gasométricas y metabólicas de las altas presiones transitorias del neumoperitoneo durante un corto período de tiempo para garantizar una mayor seguridad en la introducción del primer trocar. Métodos: fueron estudiados 67 pacientes sometidos a procedimientos videolaparoscópicos y distribuidos aleatoriamente en grupo P12: n = 30 (presión intraperitoneal [PIP] de 12 mmHg), y grupo P20: n = 37 (PIP de 20 mmHg). Se evaluó la presión arterial media por cateterismo de la arteria radial; y mediante gasometría, el pH, la presión parcial de oxígeno arterial, la presión parcial de CO2 arterial, el bicarbonato y la reserva alcalina. Esos parámetros fueron evaluados en ambos grupos en el tiempo cero, antes del neumoperitoneo (TP0); en el tiempo uno (TP1), cuando la PIP alcanza 12 mmHg en ambos grupos; en el tiempo 2 (TP2), después de 5 min con PIP de 12 mmHg en P12 y después de 5 min con PIP de 20 mmHg en P20; y en el tiempo 3 (TP3), después de 10 min con PIP de 12 mmHg en P12 y con PIP de retorno desde 20 mmHg a 12 mmHg, contados 10 min después de TP1 en P20. Los valores diferentes de los considerados normales para los parámetros medidos o el surgimiento de fenómenos orgánicos atípicos fueron considerados alteraciones clínicas. Resultados: hubo diferencias estadísticas significativas en el grupo P20 en la presión arterial media, en el pH, en el bicarbonato y en la reserva alcalina, pero dentro de los límites de la normalidad. No se evidenciaron alteraciones clínicas ni patológicas. Conclusiones: la presión intraabdominal alta y transitoria causa alteraciones de la presión arterial media, del pH, del bicarbonato y de la reserva alcalina sin repercusiones clínicas para el paciente.

ABSTRACT: The present work addresses a sensitivity analysis investigation of the aeroelastic stability margins for the VSB-30 sounding rocket during the atmospheric flight phase. Parametric stability analyses are performed considering variations of the inertia properties of the modular payload. Such variations can be caused by different type and/or number of experiments (payload modules). The aerodynamic model is based on a supersonic unsteady potential aerodynamic method. Freestream conditions depend on the flight speed and atmosphere. An equivalent structural dynamic model of the rocket is represented by a beam-like structure. The objective of this investigation is to establish an aeroelastic model for aeroelastic stability and response analyses, as well as a procedure for the identification of stability margins for rockets. The resulting aeroelastic model should be further used in MDO processes for the improvement of the vehicle flight performance. The results of the present effort indicate that the flutter behavior of the VSB-30 sounding rocket is sufficiently robust inside the operational envelope, even considering the environmental and loading conditions. The spinning effect, in this case, does not play a significant role, because the flutter margins remain almost unaltered with and without VSB-30 body spin.

This paper presents the effects of some convective flux computation schemes on boundary layer and shocked flow solutions. Second-order accurate centered and upwind convective flux computation schemes are discussed. The centered Jameson scheme, plus explicitly added artificial dissipation terms are considered. Three artificial dissipation models, namely a scalar and a matrix version of a switched model, and the CUSP scheme are available. Some implementation options regarding these methods are proposed and addressed in the paper. For the upwind option, the Roe flux-difference splitting scheme is used. The CUSP and Roe schemes require property reconstructions to achieve second-order accuracy in space. A multidimensional limited MUSCL interpolation method is used to perform property reconstruction. Extended multidimensional limiter formulation and implementation are here proposed and verified. Theoretical flow solutions are used in order to provide a representative testbed for the current study. It is observed that explicitly added artificial dissipation terms of the centered scheme may nonphysically modify the numerical solution, whereas upwind schemes seem to better represent the flow structure.

Abstract The work reported in the present paper was performed to honor the centennial of the flight by Alberto Santos Dumont with his 14-Bis aircraft. The paper describes results for a computational fluid dynamics (CFD) analysis of the 14-Bis aircraft aerodynamics and flight stability. The 14-Bis aircraft geometry was generated from historical sources and observations. CFD computations were performed using well-established commercial codes for calculation of the historical flight conditions. Simulations considered a Reynolds-averaged Navier-Stokes formulation, in which turbulence closure was achieved by using Menter's model. The flight conditions investigated were primarily concerned with historical observations regarding flight speeds and the need for a more powerful engine, as well as flight stability characteristics of the 14-Bis airplane, which are unknown up to the present day. The results led to qualitative agreement with historical reports, although quite interesting conclusions could be drawn with regard to the actual aerodynamic flight speeds and the aircraft stability parameters.

Abstract: Aerodynamic flow simulations over a typical sounding rocket are presented in this paper. The work is inserted in the effort of developing computational tools necessary to simulate aerodynamic flows over configurations of interest for Instituto de Aeronáutica e Espaço of Departamento de Ciência e Tecnologia Aeroespacial. Sounding rocket configurations usually require fairly large fins and, quite frequently, have more than one set of fins. In order to be able to handle such configurations, the present paper presents a novel methodology which combines both Chimera and patched multiblock grids in the discretization of the computational domain. The flows of interest are modeled using the 3-D Euler equations and the work describes the details of discretization procedure, which uses a finite difference approach for structure, body-conforming, multiblock grids. The method is used to calculate the aerodynamics of a sounding rocket vehicle. The results indicate that the present approach can be a powerful aerodynamic analysis and design tool.

OBJETIVO: Verificar a eficiência da punção com agulha de Veress no hipocôndrio esquerdo, a acurácia dos testes descritos para o correto posicionamento intraperitoneal da ponta da agulha de Veress em população não selecionada. MÉTODOS: Noventa e um pacientes, sem quaisquer critérios de exclusão, consecutivamente agendados para procedimentos videolaparoscópicos, tiveram a parede abdominal puncionada no hipocôndrio esquerdo. Os pacientes receberam anestesia geral e ventilação controlada mecânica segundo o protocolo. Após a punção foram utilizadas cinco provas para testar o posicionamento da ponta da agulha no interior da cavidade peritoneal: prova da aspiração - PA, da resistência à infusão - Pres, da recuperação do líquido infundido - Prec, prova do gotejamento - PG, e a prova da pressão intraperitoneal inicial - PPII. Os resultados foram considerados para cálculo da sensibilidade (S) e da especificidade (E) e valores preditivos positivos (VPP) e valores preditivos negativos (VPN). Métodos inferenciais estatísticos foram utilizados na análise dos achados. RESULTADOS: Ocorreram 13 fracassos. A PA teve E=100% e VPN=100%. Pres teve S=100%; E=0; VPP=85,71% VPN= não se aplica. Prec: S=100%; E= 53,84%; VPP= 92,85%; VPN= 100%. PG: S=100%; E= 61,53%; VPP= 93,97% VPN= 100%. Na PPII, a S, E, VPP e VPN foram de 100%. CONCLUSÃO: A punção no hipocôndrio esquerdo é eficiente, as provas realizadas orientam o cirurgião a despeito do gênero, IMC ou operações prévias.

Objective: To assess the effectiveness of the Veress needle puncture in the left hypochondrium and the accuracy of the tests described for the intraperitoneal correct positioning of the tip of the Veress needle in an unselected population. Methods: Ninetyone patients consecutively scheduled for Videolaparoscopy had the abdominal wall punctured in the left hypochondrium. There were no exclusion criteria. The patients received general anesthesia and mechanical ventilation according to the protocol. After puncturing five tests were used to confirm the positioning of the needle tip within the peritoneal cavity: aspiration test - AT; resistance to infusion - Pres; recovery of the infused fluid - Prec, dripping test - DT, and test of initial intraperitoneal pressure - IIPP. The test results were compared with results from literature for groups with defined exclusion criteria. The results were used for calculating sensitivity (S) specificity (E), positive predictive value (PPV) and negative predictive value (NPV). Inferential statistical methods were used to analyze the findings. Results: There were 13 failures. AT had E = 100% and NPV 100%. Pres had S = 100%, E = 0; PPV = 85.71%; NPV does not apply. Prec: S = 100%, E = 53.84%, PPV = 92.85%, NPV = 100%. DT: S = 100%, E = 61.53%, PPV = 93.97% NPV 100%. In IIPP, S, E, PPV and NPV were 100%. Conclusion: The puncture in the left hypochondrium is effective and the performed tests guide the surgeon regardless of sex, BMI, or previous laparotomy.

The present work implements the spectral finite volume scheme in a cell centered finite volume context for unstructured meshes. The 2-D Euler equations are considered to represent the flows of interest. The spatial discretization scheme is developed to achieve high resolution and computational efficiency for flow problems governed by hyperbolic conservation laws, including flow discontinuities. Such discontinuities are mainly shock waves in the aerodynamic studies of interest in the present paper. The entire reconstruction process is described in detail for the 2nd to 4th order schemes. Roe's flux difference splitting method is used as the numerical Riemann solver. Several applications are performed in order to assess the method capability compared to data available in the literature. The results obtained with the present method are also compared to those of essentially nonoscillatory and weighted essentially non-oscillatory high-order schemes. There is a good agreement with the comparison data and efficiency improvements have been observed.

Abstract: The present work is concerned with the numerical simulation of hypersonic blunt body flows with chemical non-equilibrium. New theoretical and numerical formulations for coupling the chemical reaction to the fluid dynamics are presented and validated. The fluid dynamics is defined for a stationary unstructured mesh and the chemical reaction process is defined for "finite quantities" moving through the stationary mesh. The fluid dynamics is modeled by the Euler equations and the chemical reaction rates by the Arrhenius law. Ideal gases are considered. The thermodynamical data are based on JANNAF tables and Burcat's database. The algorithm proposed by Liou, known as AUSM+, is implemented in a cell-centered based finite volume method and in an unstructured mesh context. Multidimensional limited MUSCL interpolation method is used to perform property reconstructions and to achieve second-order accuracy in space. The minmod limiter is used. The second order accuracy, five stage, Runge-Kutta time-stepping scheme is employed to perform the time march for the fluid dynamics. The numerical code VODE, which is part of the CHEMKIN-II package, is adopted to perform the time integration for the chemical reaction equations. The freestream reacting fluid is composed of H2 and air at the stoichiometric ratio. The emphasis of the present paper is on the description of the new methodology for handling the coupling of chemical and fluid mechanic processes, and its validation by comparison with the standard time-splitting procedure. The configurations considered are the hypersonic flow over a wedge, in which the oblique detonation wave is induced by an oblique shock wave, and the hypersonic flow over a blunt body. Differences between the solutions obtained with each formulation are presented and discussed, including the effects of grid refinement in each case. The primary objective of such comparisons is the validation of the proposed methodology. Moreover, for the hypersonic flow over a blunt body, solutions obtained for two meshes are shown, compared and analyzed. The numerical solutions are also compared with experimental data.

A detailed numerical study is presented of the order of accuracy of some proposed cell centered, finite volume schemes used for the solution of the 2-D gasdynamic equations on triangular unstructured grids. The schemes studied are based on a MUSCL-type linear reconstruction of interface properties, which seeks to achieve 2nd-order accuracy in space. They are also nominally flux-vector splitting-type schemes, and the results here presented use Liou's AUSM+ algorithm. The basic aspects effecting the scheme's order of accuracy are the form in which the reconstruction process is designed and the form in which the limiting process is performed. Two basic concepts are tested with regard to the reconstruction process, namely the use of 1-D-type and gradient-based reconstruction. The limiter can also be constructed as a 1-D-type limiter or as a truly multi-dimensional limiter. The schemes are tested on a linear convection-like model equation and the numerical solutions are compared to the analytical solution, for different mesh sizes, in order to assess the scheme's order of accuracy. For comparison purposes, the results obtained with a centered scheme are also presented. Second-order accuracy is shown to be only obtained for the centered scheme. The nominally 2nd-order upwind algorithms lead to actual orders of accuracy, which vary from 0.9 to 1.5.