Jan Denzel

Bio: Jan Denzel is an academic researcher from University of Stuttgart. The author has contributed to research in topics: Propulsion & Aerospace engineering. The author has an hindex of 2, co-authored 7 publications receiving 14 citations.

Innovative Scaled Test Platform e-Genius-Mod—Scaling Methods and Systems Design

Abstract: Future aircraft design highly depends on the successful implementation of new technologies. However, the gap between conventional designs and new visions often comes with a high financial risk. This significantly complicates the integration of innovations. Scaled unmanned aircraft systems (UAS) are an innovative and cost-effective way to get new configurations and technologies in-flight. Therefore the Institute of Aircraft Design developed the e-Genius-Mod taking into account all relevant similitude requirements. It is a scale model of the electric motor glider e-Genius. Since the Reynolds number for the free-flight model cannot be adhered to, an airfoil was developed with lift-to-drag and lift-to-angle-of-attack courses reproducing the full-scale e-Genius flight characteristics. This will enable testing and assessment of new aviation technologies in a scaled version with an opportunity for free-flight demonstration in relevant environment.

In-flight Lift and Drag Estimation of an Unmanned Propeller-Driven Aircraft

Abstract: The high-power density and good scaling properties of electric motors enable new propulsion arrangements and aircraft configurations. This results in distributed propulsion systems allowing to make use of aerodynamic interaction effects between individual propellers and the wing of the aircraft, improving flight performance and thus reducing in-flight emissions. In order to systematically analyze these effects, an unmanned research platform was designed and built at the University of Stuttgart. As the aircraft is being used as a testbed for various flight performance studies in the field of distributed electric propulsion, a methodology for precise identification of its performance characteristics is required. One of the main challenges is the determination of the total drag of the aircraft to be able to identify an exact drag and lift polar in flight. For this purpose, an on-board measurement system was developed which allows for precise determination of the thrust of the aircraft which equals the total aerodynamic drag in steady, horizontal flight. The system has been tested and validated in flight using the unmanned free-flight test platform. The article provides an overview of the measuring system installed, discusses its functionality and shows results of the flight tests carried out.

Verifying the Effect of Wingtip Propellers on Drag Through In-Flight Measurements

Abstract: This work presents the effect of wingtip-mounted propellers on the aircraft drag polar, identified from in-flight measurements. In previous wind-tunnel experiments, significant reductions in drag a...

Automatic Take-Off and Landing of Tailwheel Aircraft with Incremental Nonlinear Dynamic Inversion

Abstract: This work presents a control and guidance algorithm for automated tailwheel aircraft operation during takeoff and landing. The particular suitability of incremental control concepts for this application is shown to lie in the improved capability to deal with model uncertainties using measurements. Existing incremental controllers for fixed-wing aircraft are extended to support and improve the usability specifically for automatic takeoffs and landings. Flight test results demonstrate the potential of the presented method and underline the theoretical results.

Aircraft Hybrid-Electric Propulsion: Development Trends, Challenges and Opportunities

Abstract: The present work is a survey on aircraft hybrid electric propulsion (HEP) that aims to present state-of-the-art technologies and future tendencies in the following areas: air transport market, hybrid demonstrators, HEP topologies applications, aircraft design, electrical systems for aircraft, energy storage, aircraft internal combustion engines, and management and control strategies. Several changes on aircraft propulsion will occur in the next 30 years, following the aircraft market demand and environmental regulations. Two commercial areas are in evolution, electrical urban air mobility (UAM) and hybrid-electric regional aircraft. The first one is expected to come into service in the next 10 years with small devices. The last one will gradually come into service, starting with small aircraft according to developments in energy storage, fuel cells, aircraft design and hybrid architectures integration. All-electric architecture seems to be more adapted to UAM. Turbo-electric hybrid architecture combined with distributed propulsion and boundary layer ingestion seems to have more success for regional aircraft, attaining environmental goals for 2030 and 2050. Computational models supported by powerful simulation tools will be a key to support research and aircraft HEP design in the coming years. Brazilian research in these challenging areas is in the beginning, and a multidisciplinary collaboration will be critical for success in the next few years.

In-flight Lift and Drag Estimation of an Unmanned Propeller-Driven Aircraft

Abstract: The high-power density and good scaling properties of electric motors enable new propulsion arrangements and aircraft configurations. This results in distributed propulsion systems allowing to make use of aerodynamic interaction effects between individual propellers and the wing of the aircraft, improving flight performance and thus reducing in-flight emissions. In order to systematically analyze these effects, an unmanned research platform was designed and built at the University of Stuttgart. As the aircraft is being used as a testbed for various flight performance studies in the field of distributed electric propulsion, a methodology for precise identification of its performance characteristics is required. One of the main challenges is the determination of the total drag of the aircraft to be able to identify an exact drag and lift polar in flight. For this purpose, an on-board measurement system was developed which allows for precise determination of the thrust of the aircraft which equals the total aerodynamic drag in steady, horizontal flight. The system has been tested and validated in flight using the unmanned free-flight test platform. The article provides an overview of the measuring system installed, discusses its functionality and shows results of the flight tests carried out.

Verifying the Effect of Wingtip Propellers on Drag Through In-Flight Measurements

Abstract: This work presents the effect of wingtip-mounted propellers on the aircraft drag polar, identified from in-flight measurements. In previous wind-tunnel experiments, significant reductions in drag and an increase in propulsive efficiency through interaction between induced flow by the wingtip-mounted propellers and the flowfield of the wing itself have been claimed. So far, however, these effects have never been verified in actual flight. That gap is closed here by presenting the results of in-flight measurements. A 33.3% scaled version of the manned, electric e-Genius aircraft has been fitted with a wingtip propulsion system and an elaborate measurement system, which allows quantifying the aforementioned effects. The drag polar is deduced through weighted least-squares parameter estimation for different settings and configurations of the wingtip propellers. The findings are compared to results from previous wind-tunnel experiments. The paper further discusses secondary effects that were observed during the flight tests and their influence on the general potential of wingtip propulsion.