Aerospace Engineering Commons^™

Chemistry Model For Ablating Carbon-Phenolic Material During Atmospheric Re-Entry, Alexandre Martin, Iain D. Boyd, Ioana Cozmuta, Michael J. Wright

Alexandre Martin

Recent and future re-entry vehicle designs, such as the CEV, use ablative material as the main component of the heat shield of their thermal protection system. In order to properly predict the behavior of the vehicle, it is imperative to take into account the gases produced by the ablation process when modeling the reacting flow environment. In the case of charring ablators, where an inner resin is pyrolyzed at a relatively low temperature, the composition of the gas expelled in the boundary layer is complex and might lead to thermal chemical reactions that cannot be captured with simple flow chemistry …

Cost-Benefit Analysis Of Error Reduction For Complex Systems, Robert A. Mcdonald

Robert A. McDonald

The cost-benefit tradeoff of analysis fidelity in complex systems analysis has been posed as an optimization problem providing quantitative guidance for investment in improving analysis. A nonlinear constrained optimizer to solve this problem has been integrated into an error tradeoff environment providing an intuitive tool for the decision maker to consider investment in fidelity at the same time as design decisions are considered. An example demonstrates the efficacy of the improved interface to enable fidelity improvement investment decisions.

Multidisciplinary Design Optimization Of An Extreme Aspect Ration Hale Uav, Bryan Morrisey, Robert A. Mcdonald

Robert A. McDonald

Development of High Altitude Long Endurance (HALE) aircraft systems is part of a vision for a low cost communications/surveillance capability. Applications of a multi payload aircraft operating for extended periods at stratospheric altitudes span military and civil genres and support battlefield operations, communications, atmospheric or agricultural monitoring, surveillance, and other disciplines that may currently require satellite-based infrastructure. The central goal of this research was the development of a multidisciplinary tool for analysis, design, and optimization of HALE UAVs, facilitating the study of a novel configuration concept. Applying design ideas stemming from a unique WWII-era project, a "pinned wing" HALE aircraft …

Design And Cfd Analysis Of Mass Transfer And Shear Stresses Distributions In Airlift Reactor, Rachid Bannari, Brahim Selma, Abdelfettah Bannari, Pierre Proulx

Abdelfettah Bannari Ph.D

The design, scale-up and performance evaluation of biological reactors require accurate information about the gas-liquid flow dynamics. In this study, we use CFD techniques to investigate important parameters of the multiphase flow dynamics on an initial airlift bioreactor in order to improve its design. Such parameters are distributions of shear stresses and mass transfer. Our initial proposed design of the airlift bioreactor was used for biomass growing. Specifically to produce cellulase enzyme using the fungus Trichoderma Reesei. However, the morphology of the microorganism obtained in this bioreactor was not appropriated to produce cellulase. Since the microorganism morphology presented a small …

Strongly Coupled Computation Of Material Response And Nonequilibrium Flow For Hypersonic Ablation, Alexandre Martin, Iain D. Boyd

Alexandre Martin

A one-dimensional material response implicit solver with surface ablation and pyrolysis is strongly coupled to LeMANS, a CFD code for the simulation of weakly ionized hypersonic flows in thermo-chemical non-equilibrium. Using blowing wall boundary conditions and a moving mesh algorithm, the results of a strongly coupled solution of a re-entry problem are presented, using the well defined case of the IRV-2 vehicle. Results are compared to other coupled codes and show good agreement with published numerical results.

A Coupled Cfd-Kinetic Models For Cellulase Production In Airlift Reactor, Rachid Bannari, Abdelfettah Bannari, Brahim Selma, Pierre Proulx

Abdelfettah Bannari Ph.D

Cellulase production provides a catalyst for cellulose hydrolysis to glucose, to be used for eventual production of ethanol. The transport of reactants may influence the reaction rate remarkably, for the biological reaction, especially the enzymatic reaction, The transport behavior of the components in a biological system should be considered in the model. In this work, we propose a coupled model between hydrodynamics (twoPhaseEuler- Foam) and a kinetic model for batch and fed-batch cellulase enzyme production by T. reesei from cellulose/lactose substrate which is constructed from literature concepts and laboratory data. Good agreement is obtained between the results and experimental data.

A User Friendly Interface For Gaussian Process Metamodeling, Collin R. Baukol, Robert A. Mcdonald, Nicholas Delmas

Robert A. McDonald

As research into metamodeling and using advanced metamodeling techniques continues, it is important to remember design engineers who need to use these advancements. Even experienced engineers may not be well versed in the material and mathematical background that is currently required to generate and fully comprehend advanced complex metamodels. A user friendly metamodeling environment is being developed to help bridge the gap that is currently growing between the research community and the design engineers. This tool allows users to easily create, modify, and assess the quality of metamodels.

Senior Design At Cal Poly: A Recipe For Success, Robert A. Mcdonald, Jordi Puig-Suari, Dave Esposto, Bruce Wright

Robert A. McDonald

The Aerospace Engineering Department at Cal Poly has, over the years, evolved a unique recipe for Senior Design. This recipe has been applied to the capstone Aircraft and Spacecraft design courses and will soon be extended to an Unmanned Aerial Vehicle design course. This recipe consists primarily of a year long design sequence with a great deal of participation from the region's aerospace industry. The Cal Poly recipe has proven to be both flexible and effective. The authors believe it could be adapted and applied in a similar manner at other institutions with a similar degree of success.

Underpowered Aircraft - Performance And Operational Possibilities, Andrew S. Ezzard, Michael R. Vallone, Robert A. Mcdonald

Robert A. McDonald

A unique configuration, known as an Underpowered Aircraft, allows for the modification of gliding flight vehicles for increased range and lower cost when compared with fully powered flight vehicles. Intentionally under-sizing the powerplant for a flight vehicle allows the designer to choose a powerplant that will not only perform the mission requirements, but will also provide the customer with the most cost effective solution, as some missions may not require fully powered flight. Specifically, the underpowered aircraft concept studied in this paper is a gliding flight aircraft that does not have enough power for climbing or level flight, but does …

Space Settlements, Property Rights, And International Law: Could A Lunar Settlement Claim The Lunar Real Estate It Needs To Survive?, Alan Wasser, Douglas Jobes

Alan Wasser

The settlement of space and the expansion of the habitat of humanity beyond Earth will benefit all mankind but will be astronomically expensive. Private enterprise would do it if there were a sufficient profit potential, something only Lunar and Martian real estate is valuable enough to provide. Utilization of this tremendous potential value as an incentive has been prevented by the mistaken assumption that the 1967 Outer Space Treaty's prohibition of "national appropriation" and requirement of national supervision of private activities prohibit private property in space. This paper attempts to demonstrate, by expert legal consensus, that the 1967 Outer Space …

An Improved Robust Projection Identification Algorithm To Manned Maneuvering Units, Bin Xu

Bin Xu

空间载人机动装置(MMU )在进行救援过程中, 其动力学参数存在很大的不确定性。为解决这一辨识问题, 本文首先推导系统关于各动力学参数的线性化模型, 然后结合该线性模型的特点, 提出了一种用于估计动力学参数的改进鲁棒投影算法, 并在理论上分析了该算法的收敛性质, 数字仿真验证了方法的有效性。

Pid Parameter Optimization Of An Uav Longitudinal Flight Control System, Kamran Turkoglu, Ugur Ozdemir, Melike Nikbay, Elbrous M. Jafarov

Kamran Turkoglu

In this paper, an automatic control system design based on Integral Squared Error (ISE) parameter optimization technique has been implemented on longitudinal flight dynamics of an UAV. It has been aimed to minimize the error function between the reference signal and the output of the plant. In the following parts, objective function has been defined with respect to error dynamics. An unconstrained optimization problem has been solved analytically by using necessary and sufficient conditions of optimality, optimum PID parameters have been obtained and implemented in control system dynamics.

The Role Of Error In The Conceptual Design Of A Transport Aircraft, Robert A. Mcdonald

Robert A. McDonald

A fidelity trade environment was demonstrated by using it to simulate a decision making process for a transport aircraft. This scenario was not possible without the fidelity trade environment. The role of system feedback and coupling in error stability was also investigated.
A sensitivity approach which relies on the system sensitivity matrix was used to rapidly approximate the propagation of error through the complex system. In verification tests, the sensitivity approach provided approximate results substantially similar to a Monte Carlo approach that was many orders of magnitude more expensive. The rapid sensitivity approach to modeling error propagation enabled the responsive …

Forest Products Laboratory: Supporting The Nation's Armed Forces With Valuable Wood Research For 90 Years, Christopher D. Risbrudt, Robert J. Ross, Julie J. Blankenburg, Charles A. Nelson

Julie Blankenburg

Founded in 1910 by the U.S. Forest Service to serve as a centralized, national wood research laboratory, the USDA Forest Products Laboratory (FPL) has a long history of providing technical services to other government agencies, including those within the Department of Defense (DoD). A recent search of FPL’s library and correspondence files revealed that approximately 10,000 articles, reports, manuals, other technical publications, and communications have been generated and provided to the DoD since 1910. FPL has provided support on a broad array of technical questions—from designporting materiel to Europe and the South Pacific during World War II to assisting in …

Error Allocation In Complex Systems Design, Robert A. Mcdonald

Robert A. McDonald

A fidelity trade environment was conceived, formulated, developed, and demonstrated. This development relied on the advancement of enabling techniques including error propagation, metamodeling, and information management. These techniques were integrated with an existing commercial systems design framework and an intuitive graphical interface to create a fidelity trade environment. A sensitivity approach to the propagation of error through complex systems was developed. This approach relied on the system sensitivity matrix to model the behavior of a complex system as a whole. In verification tests, the sensitivity approach provided approximate results substantially similar to a Monte Carlo approach that was many orders …

Large It Project Implementation - A Police Application Perspective, Venkateswar P. Oruganti

Venkateswar P Oruganti FIETE FIE PMP

A comprehensive Police Information System has the paramount objective to computerize activities related to Crime control, administrative support functions and interactions with other co-functionary government departments such as Judiciary, Road Transport Authority, Prisons, Hospitals, immigration etc., apart from providing timely and accurate information to citizens.

Effective implementation of such system depends primarily on the environment, processes, infrastructure, and continuity measures. The implementation of such systems will bring in an Organizational Transformation bridging the digital divide in a department in particular and in the government in general.

Seven Steps For Effective Implementation Of Police Information Systems, Venkateswar P. Oruganti

Venkateswar P Oruganti FIETE FIE PMP

Police Information Systems implementation from concept to completion is a unique experience. This presentation highlights typical of the practices and seven steps for effective implementation of Police Information Systems. This presentation is used for a webinar during the 2nd Anniversary of Oracle eGov COE at New Delhi in July 2005

Solution Of Multi-Species Real Gas Flows With Electric Arc And Wall Ablation, Alexandre Martin, Marcelo Reggio, Jean-Yves Trépanier

Alexandre Martin

Nozzle ablation caused by high temperature electric arc is a physical phenomenon commonly found in high voltage electrical devices. In circuit breakers, for example, the strong ablation of the PTFE nozzle wall results in the creation of new species, which implies various chemical reactions. For the simulation of these phenomena, a bi-dimensional axisymmetric Euler equations model for multi-species flow has been developed. To solve the governing equations, a finite volume method based on Roe’s flux splitting scheme [11] has been established. The proposed scheme approaches the mean-values used in Roe’s matrix in a new way. To take into account the …

A Method For Thermodynamic Work Potential Analysis Of Aircraft Engines, Robert Mcdonald

Robert A. McDonald

The objective of this paper is to provide a tool to facilitate the application of thermodynamic work potential methods to aircraft and engine analysis. This starts with a discussion of the theoretical background underlying these methods, which is then used to derive various equations useful for thermodynamic analysis of aircraft engines. The work potential analysis method is implemented in the form of a set of working charts and tables than can be used to graphically evaluate work potential stored in high-enthalpy gas. The range of validity for these charts is 300 to 36,000 °R, pressures between 0.01 and 100 atm, …

Simulation Of Inviscid Multi-Species Plasma Flow, Alexandre Martin, Marcelo Reggio, Jean-Yves Trépanier

Alexandre Martin

A multi-species solver for plasma at thermodynamical equilibrium is developed. A numerical scheme, based on Roe's, is implemented with some modification regarding the average quantities. A perfect gas treatment is carried out for validations, and a quasi-real gas treatment is also presented. The latter takes into account the changes in the composition of the gas caused by fluctuations in temperature and density.

Neptune: Un Logiciel Pour Les Écoulements De Rivière, Alexandre Martin, Marcelo Reggio, Jean-Yves Trépanier

Alexandre Martin

Une méthodologie de conception et d'analyse est développée pour la simulation des écoulements clans les rivières. La discrétisation des équations de base (Saint-Venant) est établie en fonction du schéma de Roe, développé à l'origine pour des écoulements compressibles non-visqueux. Le domaine est discrétisé en espace avec des triangles ou quadrilatères, clans un contexte de volume-finis, ce qui permet de représenter des géométries complexes. L'imposition des conditions frontières et initiales sont aussi décrites. Toutes les étapes préliminaires à la résolution du problème, ainsi que la visualisation de la solution sont gérées par la famille de logiciels PLANÈTES.

Reflexive Autopoietic Dissipative Special Systems Theory, Kent D. Palmer

Kent D. Palmer

A newly discovered approach to extending General Systems Theory as defined by George Klir through a set of Special Systems is described. General Systems Theory is distinguished from the theory of Meta-systems. Then, a hinge of three special systems is identified between systems and meta-systems. These special systems are defined by algebraic analogies. Anomalous physical phenomena are specified that exemplify the structures defined by the algebraic analogies. The extraordinary efficacious properties of these special systems are explained. These include ultra-efficiency and ultra-effectiveness. These three special systems are called dissipative, autopoietic, and reflexive. They are anomalous within general systems theory and …

Simulation Of Temperature Variation In Parachute Inflation, D. K. Chaturvedi

D. K. Chaturvedi Dr.

In this paper, the variation of temperature during parachute inflation is simulated by system dynamics methodology. In this methodology, causal loops for system have been identified and flow diagram is drawn. Flow diagram consists of flow rate variables, level variables and auxiliary variables. In causal mechanism principal feedback loops are identified. It also simplfies illustration due to various influencing factors such as pressure, rate of pressure, mass of parachute, textile characteristics, motion of folded parachute to compresion under pressure and interaction between parachute and its container/bag.