An Overview of NASA's Integrated Design and Engineering Analysis (IDEA) Environment

Historically, the design of subsonic and supersonic aircraft has been divided into separate technical disciplines (such as propulsion, aerodynamics and structures), each of which performs design and analysis in relative isolation from others. This is possible, in most cases, either because the amount of interdisciplinary coupling is minimal, or because the interactions can be treated as linear. The design of hypersonic airbreathing vehicles, like NASA's X-43, is quite the opposite. Such systems are dominated by strong non-linear interactions between disciplines. The design of these systems demands that a multi-disciplinary approach be taken. Furthermore, increased analytical fidelity at the conceptual design phase is highly desirable, as many of the non-linearities are not captured by lower fidelity tools. Only when these systems are designed from a true multi-disciplinary perspective, can the real performance benefits be achieved and complete vehicle systems be fielded. Toward this end, the Vehicle Analysis Branch at NASA Langley Research Center has been developing the Integrated Design and Engineering Analysis (IDEA) Environment. IDEA is a collaborative environment for parametrically modeling conceptual and preliminary designs for launch vehicle and high speed atmospheric flight configurations using the Adaptive Modeling Language (AML) as the underlying framework. The environment integrates geometry, packaging, propulsion, trajectory, aerodynamics, aerothermodynamics, engine and airframe subsystem design, thermal and structural analysis, and vehicle closure into a generative, parametric, unified computational model where data is shared seamlessly between the different disciplines. Plans are also in place to incorporate life cycle analysis tools into the environment which will estimate vehicle operability, reliability and cost. IDEA is currently being funded by NASA?s Hypersonics Project, a part of the Fundamental Aeronautics Program within the Aeronautics Research Mission Directorate. The environment is currently focused around a two-stage-to-orbit configuration with a turbine-based combined cycle (TBCC) first stage and a reusable rocket second stage. IDEA will be rolled out in generations, with each successive generation providing a significant increase in capability, either through increased analytic fidelity, expansion of vehicle classes considered, or by the inclusion of advanced modeling techniques. This paper provides the motivation behind the current effort, an overview of the development of the IDEA environment (including the contents and capabilities to be included in Generation 1 and Generation 2), and a description of the current status and detail of future plans

Overview of NASA's Integrated Design and Engineering Analysis (IDEA)Environment

Historically, the design of subsonic and supersonic aircraft has been divided into separate technical disciplines (such as propulsion, aerodynamics and structures) each of which performs their design and analysis in relative isolation from others. This is possible in most cases either because the amount of interdisciplinary coupling is minimal or because the interactions can be treated as linear. The design of hypersonic airbreathing vehicles, like NASA s X-43, is quite the opposite. Such systems are dominated by strong non-linear interactions between disciplines. The design of these systems demands that a multi-disciplinary approach be taken. Furthermore, increased analytical fidelity at the conceptual design phase is highly desirable as many of the non-linearities are not captured by lower fidelity tools. Only when these systems are designed from a true multi-disciplinary perspective can the real performance benefits be achieved and complete vehicle systems be fielded. Toward this end, the Vehicle Analysis Branch at NASA Langley Research Center has been developing the Integrated Design & Engineering Analysis (IDEA) Environment. IDEA is a collaborative environment for parametrically modeling conceptual and preliminary launch vehicle configurations using the Adaptive Modeling Language (AML) as the underlying framework. The environment integrates geometry, configuration, propulsion, aerodynamics, aerothermodynamics, trajectory, closure and structural analysis into a generative, parametric, unified computational model where data is shared seamlessly between the different disciplines. Plans are also in place to incorporate life cycle analysis tools into the environment which will estimate vehicle operability, reliability and cost. IDEA is currently being funded by NASA s Hypersonics Project, a part of the Fundamental Aeronautics Program within the Aeronautics Research Mission Directorate. The environment is currently focused around a two-stage-to-orbit configuration with a turbine based combined cycle (TBCC) first stage and reusable rocket second stage. This paper provides an overview of the development of the IDEA environment, a description of the current status and detail of future plans

Atrial Fibrillation Induction in a Pediatric Patient during Adenosine Administration

Adenosine by rapid intravenous bolus is frequently utilized in clinical practice as both a pharmacologic treatment for supraventricular (reentrant) tachycardia and in provocative testing for the diagnosis of Wolff-Parkinson-White (WPW) syndrome. This is a case report of an otherwise healthy adolescent female who received adenosine during a provocative test for WPW syndrome. Immediately after receiving adenosine, the patient had a self-limited episode of atrial fibrillation. When administering adenosine, teams should be aware of the potential adverse effects and be prepared to treat appropriately

Policy lessons from a simple open - economy model

The authors show how two-sector models can be used to derive policy lessons about adjustment in developing economies. In the past two decades, changes in the external environment and in economic policies have been the key factors in the performance of developing economies. By and large the shocks have involved the external sector: terms-of-trade shocks or cutbacks in foreign capital. The policy responses most commonly proposed have targeted the external sector: depreciating the real exchange rate or reducing distortionary taxes to make the economy more competitive. The authors provide a starting point for analyzing the relation between external shocks and policy responses. Starting from a small, one-country, two-sector, three-good (1-2-3) model, the authors outline how the effects of a foreign capital inflow and terms-of-trade shock can be analyzed. They derive the assumptions underlying the conventional policy recommendation of real exchange rate depreciation in response to adverse shocks. The implications of such trade and fiscal policy instruments as export subsidies, import tariffs, and domestic indirect taxes can also be studied in this framework. The authors show that the standard advice to depreciate the real exchange rate in the wake of an adverse terms-of-trade shock rests on the condition that the income effect of the external shock dominates its substitution effect. But, depending on the characteristics of the economy (for example, the trade elasticities), policy results may run counter to received wisdom. For example, when the substitution effect ofan adverse external shock dominates, real depreciation is inappropriate. An infusion of foreign capital does not necessarily benefit the nontradable sector, as the results of"Dutch disease"models suggest (for example, in the extreme case of nearly infinite substitution elasticity between imports and domestic goods). When import tariffs are significant sources of public revenue, potential revenue losses from tariff cuts must be offset by other revenue sources to maintain the external current account balance. The paper shows a simple way to calculate the necessary tax adjustment. A major advantage of small models is their simplicity. The example in this paper can be solved analytically - either graphically or algebraically. It also can be solved numerically, using such widely available PC-based spreadsheet programs as Excel. The numerical implementation involves only modest data requirements. The data that governments normally release on national income, fiscal, and balance of payments accounts are sufficient.Environmental Economics&Policies,Economic Theory&Research,Economic Stabilization,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Markets and Market Access

SACD's Support of the Hyper-X Program

NASA s highly successful Hyper-X program demonstrated numerous hypersonic air-breathing vehicle related technologies including scramjet performance, advanced materials and hot structures, GN&C, and integrated vehicle performance resulting in, for the first time ever, acceleration of a vehicle powered by a scramjet engine. The Systems Analysis and Concepts Directorate (SACD) at NASA s Langley Research Center played a major role in the integrated team providing critical support, analysis, and leadership to the Hyper-X Program throughout the program s entire life and were key to its ultimate success. Engineers in SACD s Vehicle Analysis Branch (VAB) were involved in all stages and aspects of the program, from conceptual design prior to contract award, through preliminary design and hardware development, and in to, during, and after each of the three flights. Working closely with other engineers at Langley and Dryden, as well as industry partners, roughly 20 members of SACD were involved throughout the evolution of the Hyper-X program in nearly all disciplines, including lead roles in several areas. Engineers from VAB led the aerodynamic database development, the propulsion database development, and the stage separation analysis and database development effort. Others played major roles in structures, aerothermal, GN&C, trajectory analysis and flight simulation, as well as providing CFD support for aerodynamic, propulsion, and aerothermal analysis

X-43D Conceptual Design and Feasibility Study

NASA s Next Generation Launch Technology (NGLT) Program, in conjunction with the office of the Director of Defense Research and Engineering (DDR&E), developed an integrated hypersonic technology demonstration roadmap. This roadmap is an integral part of the National Aerospace Initiative (NAI), a multi-year, multi-agency cooperative effort to invest in and develop, among other things, hypersonic technologies. This roadmap contains key ground and flight demonstrations required along the path to developing a reusable hypersonic space access system. One of the key flight demonstrations required for systems that will operate in the high Mach number regime is the X-43D. As currently conceived, the X-43D is a Mach 15 flight test vehicle that incorporates a hydrogen-fueled scramjet engine. The purpose of the X-43D is to gather high Mach number flight environment and engine operability information which is difficult, if not impossible, to gather on the ground. During 2003, the NGLT Future Hypersonic Flight Demonstration Office initiated a feasibility study on the X-43D. The objective of the study was to develop a baseline conceptual design, assess its performance, and identify the key technical issues. The study also produced a baseline program plan, schedule, and cost, along with a list of key programmatic risks

Mathematical analysis of a model for the growth of the bovine corpus luteum

The corpus luteum (CL) is an ovarian tissue that grows in the wound space created by follicular rupture. It produces the progesterone needed in the uterus to maintain pregnancy. Rapid growth of the CL and progesterone transport to the uterus require angiogenesis, the creation of new blood vessels from pre-existing ones, a process which is regulated by proteins that include fibroblast growth factor 2 (FGF2).\ud \ud In this paper we develop a system of time-dependent ordinary differential equations to model CL growth. The dependent variables represent FGF2, endothelial cells (ECs), luteal cells, and stromal cells (like pericytes), by assuming that the CL volume is a continuum of the three cell types. We assume that if the CL volume exceeds that of the ovulated follicle, then growth is inhibited. This threshold volume partitions the system dynamics into two regimes, so that the model may be classified as a Filippov (piecewise smooth) system.\ud \ud We show that normal CL growth requires an appropriate balance between the growth rates of luteal and stromal cells. We investigate how angiogenesis influences CL growth by considering how the system dynamics depend on the dimensionless EC proliferation rate, p5. We find that weak (low p5) or strong (high p5) angiogenesis leads to ‘pathological’ CL growth, since the loss of CL constituents compromises progesterone production or delivery. However, for intermediate values of p5, normal CL growth is predicted. The implications of these results for cow fertility are also discussed. For example, inadequate angiogenesis has been linked to infertility in dairy cows

An Overview of the Role of Systems Analysis in NASA's Hypersonics Project

NASA's Aeronautics Research Mission Directorate recently restructured its Vehicle Systems Program, refocusing it towards understanding the fundamental physics that govern flight in all speed regimes. Now called the Fundamental Aeronautics Program, it is comprised of four new projects, Subsonic Fixed Wing, Subsonic Rotary Wing, Supersonics, and Hypersonics. The Aeronautics Research Mission Directorate has charged the Hypersonics Project with having a basic understanding of all systems that travel at hypersonic speeds within the Earth's and other planets atmospheres. This includes both powered and unpowered systems, such as re-entry vehicles and vehicles powered by rocket or airbreathing propulsion that cruise in and accelerate through the atmosphere. The primary objective of the Hypersonics Project is to develop physics-based predictive tools that enable the design, analysis and optimization of such systems. The Hypersonics Project charges the systems analysis discipline team with providing it the decision-making information it needs to properly guide research and technology development. Credible, rapid, and robust multi-disciplinary system analysis processes and design tools are required in order to generate this information. To this end, the principal challenges for the systems analysis team are the introduction of high fidelity physics into the analysis process and integration into a design environment, quantification of design uncertainty through the use of probabilistic methods, reduction in design cycle time, and the development and implementation of robust processes and tools enabling a wide design space and associated technology assessment capability. This paper will discuss the roles and responsibilities of the systems analysis discipline team within the Hypersonics Project as well as the tools, methods, processes, and approach that the team will undertake in order to perform its project designated functions

ECG Findings in Pediatric Patients under the Influence of Marijuana

Background: The effects of marijuana on the cardiac conduction system are ill defined. The purpose of this study is to describe the association between electrocardiogram (ECG) findings and positive urine drug screening (+UDS) for marijuana in the pediatric population. Methods: A retrospective review was conducted through the electronic medical record from Emergency Department (ED) visits dated 10/13- 11/14 of patients ≤ 18 years of age who tested positive for marijuana exposure by +UDS in the ED. Inclusion criteria included: 1) +UDS for marijuana performed in the ED and 2) electrocardiogram (ECG) performed on same day as +UDS. Each ECG was overread by a pediatric electrophysiologist, blinded to the results of the UDS. Results: There were 174 patients identified in the ED with a +UDS, median age of 15 years (0-18 years); 42% were male. ECG was performed at time of +UDS on 37 (21%) patients. An abnormal ECG finding was identified in 16/37 (43%), of which 15 had a follow-up ECG. Non-specific similar ECG findings were noted on 3/15: 2 ST segment changes and1 early repolarization. Significant differences were noted on ECGs with +UDS in 12/15 patients, including ST segment changes (4), left ventricular hypertrophy (3), first-degree atrioventricular (AV) block (2), and 1 each: atrial fibrillation, right ventricular hypertrophy, and Mobitz type I second-degree AV block. Conclusions: Abnormal ECG findings, including serious conduction and rhythm disturbances, can be identified in pediatric patients under the influence of marijuana. An ECG should be considered on all patients with a positive urine drug screen for marijuana