Olaf Heintze

DESIGN OF A SMART LEADING EDGE DEVICE FOR LOW SPEED WIND TUNNEL TESTS IN THE EUROPEAN PROJECT SADE

Purpose – The purpose of this paper is to describe the pre‐design and sizing of a smart leading edge section which is developed in the project SADE (Smart High Lift Devices for Next Generation Wings), which is part of the seventh framework program of the EU.Design/methodology/approach – The development of morphing technologies in SADE concentrates on the leading and trailing edge high‐lift devices. At the leading edge a smart gap and step‐less droop nose device is developed. For the landing flap a smart trailing edge of the flap is in the focus of the research activities. The main path in SADE follows the development of the leading edge section and the subsequent wind tunnel testing of a five meter span full‐scale section with a chord length of three meters in the wind tunnel T‐101 at the Russian central aero‐hydrodynamic institute (TsAGI) in Moscow.Findings – The presented paper gives an overview over the desired performance and requirements of a smart leading edge device, its aerodynamic design for the ...

Active Structure Acoustic Control for a Truck Oil Pan

The oil pan of large diesel engine trucks is a significant contributor of external noise radiation. Especially at lower frequencies below 500 Hz, this undesired broadband noise cannot be treated effectively by passive measures due to weight and size restrictions. Augmenting such systems with an Active Structural Acoustic Control (ASAC) system is a promising way to effectively damp the sound radiation at critical frequency ranges. Such a system was to be realized within the European Union (EU) project “Intelligent materials for Active Noise Reduction” (InMAR) for the oil pan of a Volvo MD13 truck engine. Piezoceramic patch actuators have been used in a laboratory test stand to alter the vibrations in a broadband noise reduction manner. This chapter discusses the actuator placement strategy and how to obtain an estimation of the broadband sound power minimization capability. Finally the chosen actuator layout was validated by experimental observations of a serial production oil pan.

The preparation of a composite structure for a first large scale ground test of a smart and gapless wing leading edge

At the Institute of Composite Structures and Adaptive Systems (FA, Prof. Wiedemann) of the DLR the structure of a flexible and gapless wing leading edge has been developed for testing in large scale structure-system ground tests. The absence of gaps in a flexible wing leading edge allows for a significant noise reduction and provides an additional key technology for realizing wings with a fully natural laminar flow. In the years 2009 and 2010 the work in the project SmartLED within the 4th German Aviation Research Program (LuFo) was focused on the preparation and realization of the first ground test of the in the project developed overall system. The overall smart droop nose concept arose from the cooperation of Airbus and EADS, whereas the DLR Institute FA dealt with the structural design, the test of the material systems, the simulation of the overall system, and the development of manufacturing technologies for the composite structures to be employed in the planned tests. The detailed presentation of this work forms the content of this paper which has been made possible through the application of the process chain for composite structures established at the Institute FA of the DLR.

Enhanced Adaptive Droop Nose—from Computer Model to Multi-functional Integrated Part

The INVENT GmbH rises in the EU project SARISTU under the lead of Airbus and in cooperation with project partners to the challenge to manufacture a composite gapless and flexible droop nose (enhanced adaptive droop nose, EADN) on the basis of computer models and in compliance with standards and requirements of industrial integration. Therefore, various individual disciplines are integrated into one single manufacturing process and, thus, into one multi-functional part. This is an iterative process which develops along the entire range of structural engineering from material and substructure specimen and tests to the design of tooling and processes. Regarding the industrial integration of the morphing wing leading edge, the individual technical disciplines such as protection against erosion, lighting strike and bird strike as well as deicing were selected for SARISTU. Based on the overall design activities of the DLR, INVENT integrates the surface protection of Airbus Group Innovations, deicing of GKN and lightning strike protection into a flexible composite structure.

Material characterization for morphing purposes in order to match flight requirements

Natural laminar flow is one of the challenging aims of the current aerospace research. Main reasons for the aerodynamic transition from laminar into turbulent flow focusing on the airfoil-structure is the aerodynamic shape and the surface roughness. The Institute of Composite Structures and Adaptive Systems at the German Aerospace Center in Braunschweig works on the optimization of the aerodynamic-loaded structure of future aircrafts in order to increase their efficiency. Providing wing structures suited for natural laminar flow is a step towards this goal. Regarding natural laminar flow, the structural design of the leading edge of a wing is of special interest. An approach for a gap-less leading edge was developed to provide a gap- and step-less high quality surface suited for natural laminar flow and to reduce slat noise. In a national project the first generation of the 3D full scale demonstrator was successfully tested in 2010. The prototype consists of several new technologies, opening up the issue of matching the long and challenging list of airworthiness requirements simultaneously. Therefore the developed composite structure was intensively tested for further modifications according to meet requirements for abrasion, impact and deicing basically. The former presented structure consists completely of glass-fiber-prepreg (GFRP-prepreg). New functions required the addition of a new material-mix, which has to fit into the manufacturing-chain of the composite structure. In addition the hybrid composites have to withstand high loadings, high bending-induced strains (1%) and environmentally influenced aging. Moreover hot-wet cycling tests are carried out for the basic GFRP-structure in order to simulate the long term behavior of the material under extrem conditions. The presented paper shows results of four-points-bending-tests of the most critical section of the morphing leading edge device. Different composite-hybrids are built up and processed. An experimental based trend towards an optimized material design will be shown.

Sound Radiation of a Large Truck Oil Pan: Estimation and Experimental Investigation

The oil pan of large diesel engine trucks has been identified as a significant contributor to their external noise radiation. This undesired broadband noise is caused by the oil pans structural vibration and can not be treated effectively by passive measures especially in the low frequency regime up to 500Hz. In order to address this challenge, an active structural acoustic control system consisting of structural sensors and actuators is suitable to alter the oil pans vibrations in a sound reducing manner. A first step is however to classify the broadband sound radiation such that it allows for a proper and efficient sound power estimation resulting from structural measurements. Therefore, an acoustical model was set up based on a geometrical surface scan of a serial production large truck oil pan mounted in a laboratory test stand. This model served for the numerical computation of a set of principle velocity patterns contributing independently to the active sound power, where its hybrid estimation has been performed employing additionally the measured structural response of the oil pan assembly due to a shaker excitation. Finally, the sound power radiation of the test stand has been measured in a reverberation room to validate this hybrid estimation.