TY - BOOK A1 - Mertens, Josef T1 - Instationäre Strömungen von Gasen mit brennbaren Partikeln Y1 - 1983 N1 - Aachen, Techn. Hochschule, Diss., 1983 CY - Aachen ER - TY - JOUR A1 - Mertens, Josef T1 - Charakteristiken des Staub-Gas-Gemisches JF - Zeitschrift für angewandte Mathematik und Mechanik : ZAMM. 65 (1985), H. 4 Y1 - 1985 SN - 1521-4001 SP - T211 EP - T213 ER - TY - JOUR A1 - Mertens, Josef A1 - Klevenhusen, K. D. A1 - Jakob, H. T1 - Accurate Transonic Wave Drag Prediction Using Simple Physical Models JF - AIAA-Journal. 25 (1987), H. 6 Y1 - 1987 SN - 0001-1452 SP - 799 EP - 805 ER - TY - JOUR A1 - Mertens, Josef A1 - Hünecke, Klaus T1 - Experimentelle Untersuchung zur Landeeigenschaft von Hyperschall-Fluggeräten / Hünecke, Klaus ; Mertens, Josef JF - DGLR-Jahrbuch 1988 Bd. 1 Y1 - 1988 N1 - DGLR-88-123 SP - 706 ER - TY - CHAP A1 - Mertens, Josef A1 - Becker, K. ED - Ballmann, Josef T1 - Numerical solution of flow equations : an aircraft designer's view T2 - Nonlinear hyperbolic equations - theory, computation methods, and applications : proceedings of the 2nd International Conference on Nonlinear Hyperbolic Problems, Aachen, FRG, March 14 to 18, 1988. - (Notes on Numerical Fluid Mechanics ; 24) N2 - Today the most accurate and cost effective industrial codes used in aircraft design are based on the full potential equation coupled with boundary layer equations. However, these are not capable to solve complicated three-dimensional problems of vortical flows and shocks. On the other hand Euler and Navier-Stokes codes are too expensive and not accurate enough for design purposes, especially in regard of drag and interference prediction. The reasons for these deficiencies are investigated and a way to overcome them by future developments is demonstrated. Y1 - 1989 SN - 3-528-08098-1 U6 - http://dx.doi.org/10.1007/978-3-322-87869-4_41 N1 - International Conference on Nonlinear Hyperbolic Problems <3, 1988, Aachen> SP - 403 EP - 412 PB - Vieweg CY - Braunschweig ER - TY - JOUR A1 - Mertens, Josef T1 - Laminar flow for supersonic transports JF - Proceedings : March 16 - 18, 1992, Congress Centrum, Hamburg, Federal Republic of Germany / organized jointly by: Deutsche Gesellschaft für Luft- und Raumfahrt e.V. ... [Programme committee J. Szodruch ...] Y1 - 1992 SN - 3-922010-73-3 N1 - DGLR-Bericht ; 92,06 SP - 319 EP - 323 PB - DGLR CY - Bonn ER - TY - CHAP A1 - Mertens, Josef ED - Sobieczky, H. T1 - Aerodynamic multi point design challenge T2 - New design concepts for high speed air transport.- (Courses and lectures / International Centre for Mechanical Sciences ; 366) N2 - In the chapter “Son of Concorde, a Technology Challenge” one of the new challenges for a Supersonic Commercial Transport (SCT) is multi-point design for the four main design points: - supersonic cruise - transonic cruise - take-off and landing - transonic acceleration. KW - Drag Reduction KW - Pitching Moment KW - Leading Edge Vortex KW - Wave Drag KW - Variable Geometry Y1 - 1997 SN - 3-2118-2815-X U6 - http://dx.doi.org/10.1007/978-3-7091-2658-5_4 SP - 53 EP - 67 PB - Springer CY - Wien [u.a.] ER - TY - CHAP A1 - Mertens, Josef ED - Sobieczky, H. T1 - Required aerodynamic technologies T2 - New design concepts for high speed air transport. - (Courses and lectures / International Centre for Mechanical Sciences ; 366) N2 - In the preceeding chapters on “Son of Concorde, a Technology Challenge” and “Aerodynamic Multipoint Design Challenge” it was explained, that a well balanced contribution of new technologies in all major disciplines is required for realisation of a new Supersonic Commercial Transport (SCT). One of these technologies - usually one of the most important for aircraft-is aerodynamics. Here, the required “pure” aerodynamic technologies are specified in more detail, according to our present knowledge. Increasing insight into the problems may change the balance of importance of the individual technologies and may require some more contributions. We must never confine our knowledge to the knowledge base of an expert at a given time, but must stay open for new insights. KW - Mach Number KW - Wind Tunnel KW - Supersonic Flow KW - Pitching Moment KW - Wave Drag Y1 - 1997 SN - 3-2118-2815-X U6 - http://dx.doi.org/10.1007/978-3-7091-2658-5_5 SP - 69 EP - 96 PB - Springer CY - Wien [u.a.] ER - TY - CHAP A1 - Mertens, Josef ED - Sobieczky, H. T1 - Certification of supersonic civil transports T2 - New design concepts for high speed air transport. - (Courses and lectures / International Centre for Mechanical Sciences ; 366) N2 - Since certification of Concorde new certification standards were introduced including many new regulations to improve flight safety. Most of these standards are to prevent severe accidents in the future which happened in the past (here: after Concorde’s certification). A new SCT has to fulfill these standards, although Concorde had none of these accidents. But accidents - although they sometimes occurred only for a specific aircraft type - have to be avoided for any (new) aircraft. Because of existing aircraft without typical accident types having demonstrated their reliability, they are allowed to go on based on their old certification; although sometimes new rules prevent accident types which are not connected to specific aircraft types - like e.g. evacuation rules. Anyway, Concorde is allowed to fly based on its old certification, and hopefully in the future will fly as safely as in the past. But a new SCT has to fulfill updated rules like any other aircraft, and it has to be “just another aircraft” [75]. KW - Noise Exposure KW - Evacuation Rule KW - Severe Accident KW - Certification Rule KW - Thermal Fatigue Testing Y1 - 1997 SN - 3-2118-2815-X U6 - http://dx.doi.org/10.1007/978-3-7091-2658-5_6 SP - 97 EP - 103 PB - Springer CY - Wien [u.a.] ER - TY - CHAP A1 - Mertens, Josef ED - Sobieczky, H. T1 - Supersonic laminar flow T2 - New design concepts for high speed air transport. - (Courses and lectures / International Centre for Mechanical Sciences ; 366) N2 - Supersonic transports are very drag sensitive. Technology to reduce drag by application of laminar flow, therefore, will be important; it is a prerequisite to achieve very long range capability. In earlier studies it was assumed that SCTs would only become possible by application of laminar flow [376]. But today, we request an SCT to be viable without application of laminar flow in order to maintain its competitiveness when laminar flow becomes available for subsonic and supersonic transports. By reducing fuel burned, laminar flow drag reduction reduces size and weight of the aircraft, or increases range capability -whereas otherwise size and weight would grow towards infinity. Transition mechanisms from laminar to turbulent state of the boundary layer flow (ALT, CFI, TSI) function as for transonic transports, but at more severe conditions: higher sweep angles, cooled surfaces; higher mode instabilities (HMI) must at least be taken into account, although they may not become important below Mach 3. Hitherto there is a worldwide lack of ground test facilities to investigate TSI at the expected cruise Mach numbers between 1.6 and 2.4; in Stuttgart, Germany one such facility -a Ludwieg tube- is still in the validation phase. A quiet Ludwieg tunnel could be a favourable choice for Europe. But it will require a new approach in designing aircraft which includes improved theoretical predictions, usage of classical wind tunnels for turbulent flow and flight tests for validation. KW - Wind Tunnel KW - Flight Test KW - Supersonic Wind Tunnel KW - Parabolized Stability Equation Y1 - 1997 SN - 3-2118-2815-X U6 - http://dx.doi.org/10.1007/978-3-7091-2658-5_18 SP - 275 EP - 290 PB - Springer CY - Wien [u.a.] ER -