Ingo Staack

Abstract: A suitable method for simulating large complex dynamic systems is represented by distributed modelling using transmission line elements. The method is applicable to all physical systems, such as me ...

Abstract: "The conceptual design is the early stage of aircraft design process where results are needed fast, both analytically and visually so that the design can be analyzed and eventually improved in the ...

Abstract: This paper looks at fuel consumption due to shaft power off-takes from the engine and the related increase in the aircraft’s fuel consumption. It presents a review and comparison of published and unpublished data on this kind of consumption. The paper presents results from the TURBOMATCH engine simulation model, calibrated to real world engine data. A generic equation is derived for the calculation of fuel consumption due to shaft power extraction. Main result is the shaft power factor kP found to be in the order of 0.002 N/W for a typical cruise flight. This yields an amazingly high efficiency for power generation by shaft power extraction from a turbo fan engine of more than 70 %.

Abstract: This paper presents the development of a design framework for the initial conceptual design phase. The focus in this project is on a flexible database in XML format, together with close integration ...

Abstract: At Linkoping University aeronautical research is focusing on design methodologies in early stages of aircraft design. Rapid design and evaluation of prototypes is considered an important branch of this work. In this paper flight test activities at the university are described, the design of a light weight affordable data acquisition system is explained and some flight test results including flow visualization are presented.

Abstract: Multidisciplinary design optimization has become a powerful technique to facilitate continuous improvement of complex and multidisciplinary products. Parametric modeling is an essential part with t ...

Abstract: This work studies an innovative working hydraulic system design for mobile applications, referred to as flow control. The fundamental difference compared to load-sensing systems is that the pump is ...

Abstract: The current development towards multiple processor cores in personal computers is making distribution and parallelization of simulation software increasingly important. The possible speedups from parallelism are however often limited with the current centralized solver algorithms, which are commonly used in today’s simulation environments. An alternative method investigated in this work utilizes distributed solver algorithms using the transmission line modeling (TLM) method. Creation of models using TLM elements to separate model components makes them very suitable for computation in parallel because larger models can be partitioned into smaller independent submodels. The computation time can also be decreased by using small numerical solver step sizes only on those few submodels that need this for numerical stability. This is especially relevant for large and demanding models. In this paper we present work in how to combine TLM and solver inlining techniques in the Modelica equation-based language, giving the potential for efficient distributed simulation of model components over several processors.

Abstract: In the scope of this thesis, a methodology for modeling of entire system architectures of commercial transport aircraft is presented. The author’s approach facilitates technology assessment of innovative system technology on aircraft-level in conceptual and early preliminary aircraft design. It closes the existing gap of sound systems modeling in early aircraft design synthesis. The proposed methodology uses a strictly function-driven approach for sizing of the single aircraft systems according to the dedicated aircraft-level functions. System weight and maximum as well as mission dependent power off-takes are estimated. The principle of energy balance is used to derive the power demand of the single systems. A modular and flexible approach has been chosen that allows for fast variation of the system architecture. Thus, investigation of large design spaces is possible. For integration and assessment of innovative systems technology, a probabilistic framework is introduced that incorporates remaining uncertainties. The proposed system model has been integrated into the Institute’s of Aeronautics and Astronautics (ILR) Multidisciplinary Integrated Conceptual Aircraft Design and Optimization (MICADO) environment. Thus, repercussions of system integration, e.g. on aircraft efficiency or performance, can be captured in a highly integrated environment. The proposed systems model is a valuable tool for sound assessment of innovative system technology on overall aircraft-level already in conceptual aircraft design. The proposed systems model has been validated against two commercial transport aircraft. Additionally, comprehensive sensitivity studies show dependencies and identify the main design drivers of the single systems. Two case studies show the added-value of integration of the proposed systems model into early aircraft design synthesis. The first case study concentrates on evaluation of the impact of engine power off-takes on aircraft performance and efficiency. The second design study focuses on integration of innovative technology into the overall system architecture and on application of the proposed probabilistic framework for considering the remaining uncertainties in design and technology assessment.

Abstract: The transmission line method is a very efficient technique for dynamic modelling of flow in pipelines, and uses delay elements to represent wave propagation. In this paper, an existing transmission line method is investigated and shown to have some deficiencies. Some adjustments are proposed to avoid these deficiencies and enhance the transient and steady-state accuracy. Very good agreement is obtained between this adjusted transmission line method and an analytical model. The method has been implemented in simulations of a number of highly dynamic systems, and has been found to be robust and reliable.