Bernd Chudoba

What Price Supersonic Speed? - A Design Anatomy of Supersonic Transportation - Part 1

The first generation of supersonic commercial transportation has seen three serious attempts to arrive at an economically and environmentally viable aircraft. The US B2707-200/300 design was cancelled early before a prototype could emerge; the Russian Tu-144 design succeeded to become the first supersonic transport but spanned only a few years of restricted airline service; the Anglo-French Concorde endured more than 27 glamorous airline service years until the last of its species was retired on 30 August 2003. This first generation was followed by a second generation of supersonic commercial transport projects in the time period between 1986 until about 1999, designs which did not proceed towards the production hardware stage. This study critically examines the anatomy of two generations of supersonic commercial transport design failures and successes in order to arrive at lessons learned free of ‘wishful thinking’. The design conditions leading to the identification of the product ‘solution space’ for an economically and environmentally acceptable supersonic commercial transport are discussed. Having assembled an understanding of the product metrics valid for supersonic commercial transports, the paper then provides an outlook for the first generation of supersonic corporate and cargo jet projects. This first generation of supersonic business jet (SSBJ) and supersonic cargo jet (SSCJ) projects spans a period of nearly two decades of development, starting from 1988 until today. The present study identifies that the product development metrics of this class of aircraft is radically different compared to the metrics valid for supersonic commercial transports. The challenges in VIP transportation and dedicated freight transportation at supersonic speeds are portrayed leading to two principal trains of thought targeting the development of the first supersonic business jet and/or supersonic cargo jet hardware: the development based on a new airframe, and alternatively the development based on an existing airframe.

A Generic Hands-On Conceptual Design Methodology Applied to a Tourist Space Access Vehicle

*† ‡ The present study summarizes the development steps required towards a generic (configuration independent) hands-on flight vehicle conceptual design synthesis methodology. This process is developed such that it can be applied to any flight vehicle class if desired. In the present context, the methodology has been put into operation for the conceptual design of a tourist Space Access Vehicle (SAV). The case study illustrates elements of the design methodology & algorithm for the class of Horizontal Takeoff and Horizontal Landing (HTHL) SAVs. The HTHL SAV design application clearly outlines how the conceptual design process can be centrally organized, executed and documented with focus on design transparency, physical understanding and the capability to reproduce results. This approach offers the project lead and creative design team a management process and tool which iteratively refines the individual design logic chosen, leading to mature design methods and algorithms. As illustrated, the HTHL SAV hands-on design methodology offers growth potential in that the same methodology can be continually updated and extended to other SAVs configuration concepts, such as the Vertical Takeoff and Vertical Landing (VTVL) SAV class. Having developed, validated and calibrated the methodology for HTHL designs in the ‘hands-on’ mode, the paper provides an outlook how the methodology will be integrated into a prototype computerized synthesis design software AVDS-PrADO SAV as a follow-on step.

Future Space Tourism Transportation Design Requirements

Space transportation remains in the pioneering stages. The current expendable space launchers are like the 1850’s Conestoga Wagons - both were launched on their respective missions but only one is on record to have returned. Most were building materials for a new start in the West. This problem was solved in the American West with the introduction of the transcontinental railroad in 1860. This undertaking required not only a great effort but substantial government support. The railroad spawned numerous entrepreneurial activities never envisioned while under construction. What might this century bring if we had a ‘railroad to space’ that embodied the characteristics of the transcontinental undertaking? The X-33 & Venture Star projects were one attempt to achieve the characteristics of that transcontinental railroad. There are others, here and in other countries, but perhaps we need to begin with a smaller first step, a small, commercial reusable vertical rocket with ballistic ascent to space altitude with a hypersonic glider return? Our challenge in space today is to develop vehicles that are in continuous use, maintained and operated on a fixed schedule despite weather or environmental hazards that move payloads not only into space but back again. The X PRIZE was a

Strategic forecasting in uncertain environments: hypersonic cruise vehicle research and development case study

10 million prize awarded to Scaled Composites as the first privately financed spaceship that launched the equivalent of three persons to an altitude of at least 100 kilometers on two consecutive flights within two weeks. What about an analogous vehicle that flies two or three times a week, every week for a number of years? A major difference is that this challenge is to be accomplished without government support or government developed vehicles. Nonetheless, across the globe, there exists an array of system components that can provide the basis for a successful space access vehicle (SAV). Clearly, the cancellation of almost all reusable SAV projects indicates a pronounced weakness of the conceptual design toolbox available to assess design risks upfront. What tool set is required for the SAV designer to enable him screening the convergence design space at the earliest and cheapest design phase? The Aerospace Vehicle Design Laboratory (AVD Lab) team at the University of Oklahoma is developing a generic SAV design synthesis environment with focus on the conceptual design phase. The lab has applied elements of this toolbox to the study of a tourist aerospace vehicle under a grant from Rocketplane Limited, Inc. The vision of the generic synthesis system, the application of the hands-on methodology to develop a low-cost tourist vehicle based on the adaptation of a Lear Jet 25/35/45 series aircraft is the focus of this presentation.

The Lockheed SR-71 Blackbird - A Senior Capstone Re-Engineering Experience

The exponentially increasing amount of information accumulated from past to current engineering projects has created an environment where repurposing existing data to support new projects is paramount to sustainable success. Strategic planning and early design decisions, specifically, occur in decision-making environments that require information support capabilities that lie outside of traditional engineering analyses. In order to advance towards a more complete planning environment, a pragmatic methodology has been developed for modern aerospace data and information collection, categorisation, and utilisation with a focus on current efforts in hypersonic vehicle research and development. The main thrust has been to provide insights into financial and technical trends that support objective programmatic and planning decision-making. The end-product is a suite of graphical decision-making interfaces, linked through a unified hypersonic database. The graphical interfaces are capable of highlighting the key project drivers along varying levels of categorisation and refinement. Aided by these newly developed data and information support interfaces covering past and present hypersonic efforts, the planner’s forecasting assessment of present and future hypersonic research and development efforts is pragmatically enriched towards a more complete managerial program-planning framework.

The Future of Electric Aircraft

The two-semester Senior Aerospace Vehicle Design I & II Capstone Course at UTA’s Mechanical and Aerospace Engineering (MAE) Department has been restructured to directly respond to industry’s demand for aerospace graduates with an understanding of how to size a flight vehicle to a mission, including industry-style reporting, teamwork, disciplinary and systems integration experience. The objective of the capstone course is to expose the aerospace senior student body to solving open-ended design problems related to a total system in a highly organized and systematic fashion, to self-manage a project from ‘cradle-to-grave’, and most importantly to experience the power and pitfalls of teamwork when operating under pressure. The paper begins with an outline of the course organization as it has been implemented at UTA-MAE from Fall 2006 onwards. The main body of the document is devoted to the perspective of the capstone senior design teaching assistant for the re-engineering of the Lockheed SR-71A Blackbird with a 27-strong capstone student ‘engineering organization’. The rationale for selecting a design case study at the caliber of a Mach 3+ aircraft is outlined. The general approach to the organization, data mining, methodology development, and finally quantification of this prominent aircraft is discussed. Special emphasis has been placed on discussing the team-challenges attributed to the technical domain of this still ‘out-of-the-box’ aircraft and the resulting student interactions throughout the project.

Feasibility study of a supersonic business jet based on the Learjet airframe

The automotive industry has already begun creating electric vehicles. Now it is time for the aerospace industry to produce a viable contender in the midst of the fossil fuel dominated industry. With this in mind, the goal is to identify the constraints and forecast which technologies need to be developed to allow electric powered aircraft to have a range capable of intra-continental travel. To complete this mission the project was divided into two distinct e orts: airframe development and the electric powertrain. Although designing an optimal airframe is important, the plane will not y without the energy storage and generation capabilities. The main focus was the research of the electric powertrain. The application of metal-air batteries was evaluated and was concluded to be a dead-end. Other energy storage solutions were explored such as structural batteries and the employment of hydrogen fuel cells. Innovative generation techniques were explored and their feasibility were analyzed to determine which technologies will buy their way into future electric aircrafts. With these technologies electric aircrafts have a ghting chance against the fossil fuel contenders. When the optimized aircraft and the electric powertrain were merged the nal product was produced. This project is driven by future technologies and environmental awareness. The goal was to simplify the whole aircraft to its essentials that play a vital role in the performance and viability of the aircraft. This aircraft is bound to cement the standards of the current aviation industry. It addresses the fuel prices and the environmental concern while taking into consideration FAA regulations. The vehicle was designed to demonstrate technology but also applies to a diverse market.

Generic stability and control for aerospace flight vehicle conceptual design

Since the dawn of the jet age, passengers on all jet transports, except Concorde, have traveled at about the same speed — a standard Mach 0 83-0 87 range as a practical compromise. After 27 years of supersonic commercial travel, British Airways and Air France retired their fleet of Concorde aircraft at the end of 2003 because it was considered no longer profitable. Clearly, with the retirement of Concorde, the world has lost the only aircraft offering passenger transportation at supersonic speeds. Over the past several years manufacturers have proposed new aircraft designs that promise an increase in transportation speeds. In particular, the business jet market appears to present a business case for an exclusive supersonic business jet (SSBJ). However, there is a key-hurdle which has, until now, prevented the successful launch of a SSBJ hardware program: the development cost for an all-new aircraft quickly eradicates the soughtafter business case. This paper presents the results of a parametric sizing study which aims to answer the following question: is it possible to drastically reduce the development effort of a supersonic business jet design by converting an existing Learjet airframe into a supersonic vehicle while sustaining FAA interest and approval? This paper discusses selected aircraft sizing trades and operations related constraints. The feasibility study indicates some level of technical plausibility for the case of converting an existing airframe into a certifiable lower-cost supersonic aircraft. Acknowledging the range of actual complications related to the task of economically modifying and certifying a legacy airframe towards a SSBJ, it appears that a larger size SSBJ offers significant technical and economical advantages which outweigh the ‘off-the-shelf’ Learjet case.

A Generic Stability and Control Tool for Conceptual Design: Prototype System Overview

The recent period has been filled with exceptionally interesting developments and advances, resulting in high-performance conventional and non-conventional manned and unmanned aircraft. Although those vehicles seem to comply well with specific mission performance requirements, one is still confronted with an apparent weakness to reliably stabilise and control throughout the flight envelope. Since the provision of satisfactory stability and control characteristics invariably compromises flight performance, it becomes essential to identify and integrate performance-optimal stability and control design solutions early during the flight vehicle definition phase. In particular, the conceptual design of integrated control effectors for advanced aircraft is far from being trivial. Never before have we been presented with such tremendous wealth of specialised data and information suitable for detail design of controls. In contrast, never before has it been necessary to approach any one of the primary design disciplines still as entirely ad hoc and inconsistent as in the case of designing controls during the conceptual design phase. This need initiated the development of a configuration independent (generic) stability and control methodology capable of sizing primary control effectors of fixed wing subsonic to hypersonic designs of conventional and unconventional, symmetric and asymmetric configuration layouts. This paper summarises the methodology concept and demonstrates its versatility and validity by analyzing selected stability and control characteristics of the Northrop YB-49 flying wing.

Earth–Moon System: Establishing a Solar System Presence

Aerospace conceptual designers are typically tasked to explore and size various vehicle concepts for a particular mission and then make the best decision possible for the vehicle’s initial configuration. This can be a daunting task due to a lack of information and design tools to adequately analyze, size, and compare dramatically different configurations. From the standpoint of available tools, an array of options are available for aerodynamics, structure, propulsion, and other individual disciplines, but a serious lack of tools exists for stability and control. Typically, stability and control at the conceptual design level is done through the use of statistical volume coefficients and reduced order models. These, however, are not always applicable for configurations other than classical tail aft configurations (TAC). Thus, a clear need for a more generic tool exists. This need has led to the development of AeroMech, a generic stability and control tool for conceptual design. This paper discusses the prototype, stand-alone system of AeroMech and demonstrates the tool’s applications through an example validation case study, The Northrop YB-49 Flying Wing.