Andreas Bardenhagen

Bio: Andreas Bardenhagen is an academic researcher from Technical University of Berlin. The author has contributed to research in topics: Conceptual design & Propulsion. The author has an hindex of 6, co-authored 18 publications receiving 87 citations.

Waverider Aerodynamics and Preliminary Design for Two-Stage-to-Orbit Missions, Part 2

Abstract: Osculating cones waveriders are evaluated for future reusable space transportation systems An integrated design program hasbeen developed by theInstitute of AircraftDesign and Structure Mechanics, which simulates the iterative design process including the main interactions between the involved disciplines Starting points are the dee nition of the design task (range, payload to orbit, mission and orbit proe le, etc )and a generic waverider shape with its aerodynamic characteristics The design program contains the geometric sizing of the aircraft shape, a realistic engine model with bookkeeping, aerodynamic load calculations, structure mass estimation with a e nite element method, thermal protection design, and a e ight-path simulation with trim control The predesign investigations focus on the design of a two-stage-to-orbit aerospace plane with a waverider-based e rst stage performing a cruise e ight from Europe to the equator with an orbiter transferring a maximum payload of 7 tons to a low Earth orbit The comparison with a conventional hypersonic cone guration indicates that it should be possible to fule ll the dee ned mission with 35% less fuel and an 11% lower takeoff weight These results underline the potential of the waverider concept Nomenclature FX, FZ = forces in longitudinal and vertical direction L D = lift over drag ratio, aerodynamic efe ciency M = pitching moment n = load factor S = wing reference area, m 2 V = maximum total aircraft volume, m 3

Hydrogen as the fuel of the future in aircrafts – Challenges and opportunities

Abstract: The use of hydrogen as a fuel in civil aviation depends largely on the mass of the tank system. A key parameter for the evaluation of mass development is the gravimetric storage density. With the goal of gaining a maximum equal operating empty weight (OEW), the resulting total mass of hydrogen (fuel) and structural mass must be at most equal to the current total tank mass. The minimum gravimetric storage density required for this is determined in this paper. The passenger aircraft ATR 72–212A, which was developed for short-range operation, serves as a reference. For the first calculation, the assumption is made that the efficiencies of the propulsion systems do not change after the storage, and the other necessary systems have an equivalent mass. For a flight range of 715NM, which corresponds to the design range, a gravimetric storage density of 19 wt% is already sufficient to cover the flight distance and to load the maximum payload. In order to avoid increased OEW, a storage density in the range of 33–35 wt% is necessary.

Tunneling Crack Initiation in Trailing-Edge Bond Lines of Wind-Turbine Blades

Abstract: Tunneling cracks are observed in the adhesive of the trailing-edge bond line of wind-turbine rotor blades subjected to high-cycle fatigue. To identify the root causes of these cracks, their initiat...

Advanced morphological approach in aerospace design during conceptual stage

Abstract: This paper presents an advanced morphological approach supporting designers and developers in their search for as well as synthesis and analysis of new engineering solutions during the conceptual design stage. The proposed method is based on the cluster analysis and the set theory, the set of rules and engineering implementations maximizing the gain of the products potential. The number of possible combinations using the standard morphological technology is extremely large. We present a mathematical framework that handles this problem. The method was evaluated with case studies of new engineering solutions in aerospace, ecology and adaptive soundproofing system. The case studies verified the significant potential of the proposed approach in comparison with the methods presently in use.

A Framework for Optimization of Hybrid Aircraft

Abstract: To achieve the goals of substantial improvements in efficiency and emissions set by Flightpath 2050, fundamentally different concepts are required. As one of the most promising solutions, electrification of the aircraft primary propulsion is currently a prime focus of research and development. Unconventional propulsion sub-systems, mainly the electrical power system, associated thermal management system and transmission system, provide a variety of options for integration in the existing propulsion systems. Different combinations of the gas turbine and the unconventional propulsion sub-systems introduce different configurations and operation control strategies. The trade-off between the use of the two energy sources, jet fuel and electrical energy, is primarily a result of the trade-offs between efficiencies and sizing characteristics of these sub-systems. The aircraft structure and performance are the final carrier of these trade-offs. Hence, full design space exploration of various hybrid derivatives requires global investigation of the entire aircraft considering these key propulsion sub-systems and the aircraft structure and performance, as well as their interactions. This paper presents a recent contribution of the development for a physics-based simulation and optimization platform for hybrid electric aircraft conceptual design. Modeling of each subsystem and the aircraft structure are described as well as the aircraft performance modeling and integration technique. With a focus on the key propulsion sub-systems, aircraft structure and performance that interfaces with existing conceptual design frameworks, this platform aims at full design space exploration of various hybrid concepts at a low TRL level.

Mechanics of composite materials

Abstract: INTRODUCTION TO COMPOSITE MATERIALS Chapter Objectives Introduction Classi?cation Recycling Fiber-Reinforced Composites Mechanics Terminology Summary Key Terms Exercise Set References MACROMECHANICAL ANALYSIS OF A LAMINA Chapter Objectives Introduction Review of De?nitions Hooke's Law for Different Types of Materials Hooke's Law for a Two-Dimensional Unidirectional Lamina Hooke's Law for a Two-Dimensional Angle Lamina Engineering Constants of an Angle Lamina Invariant Form of Stiffness and Compliance Matrices for an Angle Lamina Strength Failure Theories of an Angle Lamina Hygrothermal Stresses and Strains in a Lamina Summary Key Terms Exercise Set References APPENDIX A: MATRIX ALGEBRA Key Terms APPENDIX B: TRANSFORMATION OF STRESSES AND STRAINS Transformation of Stress Transformation of Strains Key Terms MICROMECHANICAL ANALYSIS OF A LAMINA Chapter Objectives Introduction Volume and Mass Fractions, Density, and Void Content Evaluation of the Four Elastic Moduli Ultimate Strengths of a Unidirectional Lamina Coefficients of Thermal Expansion Coefficients of Moisture Expansion Summary Key Terms Exercise Set References MACROMECHANICAL ANALYSIS OF LAMINATES Chapter Objectives Introduction Laminate Code Stress-Strain Relations for a Laminate In-Plane and Flexural Modulus of a Laminate Hygrothermal Effects in a Laminate Summary Key Terms Exercise Set References FAILURE, ANALYSIS, AND DESIGN OF LAMINATES Chapter Objectives Introduction Special Cases of Laminates Failure Criterion for a Laminate Design of a Laminated Composite Other Mechanical Design Issues Summary Key Terms Exercise Set References BENDING OF BEAMS Chapter Objectives Introduction Symmetric Beams Nonsymmetric Beams Summary Key Terms Exercise Set References INDEX

A review of concepts, benefits, and challenges for future electrical propulsion-based aircraft

Abstract: Electrification of the propulsion system has opened the door to a new paradigm of propulsion system configurations and novel aircraft designs, which was never envisioned before. Despite lofty promises, the concept must overcome the design and sizing challenges to make it realizable. A suitable modeling framework is desired in order to explore the design space at the conceptual level. A greater investment in enabling technologies, and infrastructural developments, is expected to facilitate its successful application in the market. In this review paper, several scholarly articles were surveyed to get an insight into the current landscape of research endeavors and the formulated derivations related to electric aircraft developments. The barriers and the needed future technological development paths are discussed. The paper also includes detailed assessments of the implications and other needs pertaining to future technology, regulation, certification, and infrastructure developments, in order to make the next generation electric aircraft operation commercially worthy.

Waverider Aerodynamics and Preliminary Design for Two-Stage-to-Orbit Missions, Part 1

Abstract: The influence of the planform shape of osculating cones waveriders on the aerodynamic behavior with respect to the longitudinal motion is discussed. The inviscid flowfield around the configurations is simulated along the complete trajectory of an airbreathing two-stage-to-orbit system based on the solution of the Euler equations. Grid refinement studies, as well as wind-tunnel results, are presented to demonstrate the validation and accuracy of the code. Furthermore, special attention is drawn to the fluid-structure interaction with respect to the heating of the leading edge under hypersonic flight conditions. It is found that the modification of a gothic planform toward combined forebody-delta wing planforms allows a significant improvement of the aeordynamic efficiency L/D in sub- and transonic flows. In addition, the longitudinal stability is increased without compromising the favorable high-speed qualities. These benefits are partly diminished by an increasing neutral point shift along the trajectory. In Part 2 (Heinze, W., and Bardenhagen, A., "Waverider Aerodynamics and Preliminary Design for Two-Stage-to Orbit Missions, Part 2," Journal of Spacecraft and Rockets, Vol. 35, No. 4, 1998, pp. 459-466), the impact of the aerodynamic effects on the integrated design and performance of a waverider-based two-stage.to-orbit system is presented.