scholarly journals Experimental and numerical studies on small contra-rotating electrical ducted fan engines

2021 ◽  
Author(s):  
Tobias Ebus ◽  
Markus Dietz ◽  
Andreas Hupfer
Keyword(s):  
Pressure Ratio ◽  
Future Research ◽  
Electric Motors ◽  
Ducted Fan ◽  
Engine Design ◽  
Ansys Cfx ◽  
Extensive Test ◽  
Electrical Propulsion ◽  
Compact Design ◽  
Heating Up

AbstractElectrical propulsion has been identified as one of the key fields of future research within the aerospace sector. The Institute of Aeronautical Engineering at the Universität der Bundeswehr München aims to contribute to the ongoing development of small-sized electrical ducted fan engines with a thrust in the range of 100 N. A special emphasis is placed on electrically powered contra-rotating fan stages. When compared to a conventional rotor–stator stage, contra-rotating fan stages allow for a more compact design, considering a given pressure ratio, or an increased pressure ratio at a constant fan diameter. Since numerous new aircraft concepts are presently being developed, a high demand for compact and powerful electrically driven engines arises. Electrically driven contra-rotating fan engines provide a high potential in terms of compactness, emissions and efficiency. Using electric motors offers the ability to overcome common issues, such as design and integration of a contra-rotating stage into a gas turbine. An innovative new engine design featuring such a contra-rotating stage is developed and tested at one of the Institute’s test benches for electrical propulsion. Key components are two brushless motors powering the fan stage, one for each rotor. Various operation points are investigated experimentally during an extensive test campaign. Experimental results are compared to results of numerical simulations computed by ANSYS CFX. Results indicate a good agreement between experiment and simulation. The engine is running very smooth throughout all tested operation points. Yet, intensive heating up of the electric motors and high-temperature zone are found to be an issue at higher rotation speeds.

Exploring GasTurb 12 for Supplementary Use on an Introductory Propulsion Design Project

2017 ◽  
Author(s):  
Aaron R. Byerley ◽  
Kurt P. Rouser ◽  
Devin O. O’Dowd
Keyword(s):  
System Analysis ◽  
Pressure Ratio ◽  
Supplementary Information ◽  
Design System ◽  
Inlet Temperature ◽  
Turbofan Engine ◽  
Design Project ◽  
Engine Design ◽  
Aeronautical Engineering ◽  
Engine Cycle

The purpose of this paper is to explore GasTurb 12, a commercial gas turbine engine performance simulation program, for supplementary use on an introductory propulsion design project in an undergraduate course. This paper will describe several possible opportunities for supplementing AEDsys (Aircraft Engine Design System Analysis) version 4.012, the engine design software tool currently in use. The project is assigned to juniors taking their first propulsion course in the aeronautical engineering major at the USAF Academy. This course, Aeronautical Engineering 361, which focuses on cycle analysis and selection, is required of all aero majors and is used to satisfy the ABET Program Criterion requiring knowledge of propulsion fundamentals. This paper describes the most recent design project that required the students to re-engine the USAF T-38 with the aim of competing for the Advanced Pilot Training Program (T-X) program. The goal of the T-X program is to replace the T-38 aircraft that entered service in 1961 with an aircraft capable of sustained high-G operations that is also more fuel efficient. The design project required the students to select an engine-cycle for a single, non-afterburning, mixed stream, low bypass turbofan engine to replace the two J85 turbojets currently in the T-38. It was anticipated that the high specific thrust requirements might possibly be met through the use of modern component measures of merit to include a much higher turbine inlet temperature. Additionally, it was anticipated that the required 10% reduction in thrust specific fuel consumption might possibly be achieved by using a turbofan engine cycle with a higher overall pressure ratio. This paper will describe the use of GasTurb 12 to perform the same design analysis that was described above using AEDsys as well as additional features such as numerical optimization, temperature-entropy diagrams, and the generation of scaled, two-dimensional engine geometry drawings. The paper will illustrate how GasTurb 12 offers important supplementary information that will deepen student understanding of engine cycle design and analysis.

Benefit and Critical Factors for the Performance of the Boundary Layer Ingesting Propulsion

2020 ◽  
Author(s):  
B. J. Lee ◽  
May-Fun Liou ◽  
Mark Celestina ◽  
Waiming To
Keyword(s):  
Boundary Layer ◽  
Pressure Ratio ◽  
Velocity Ratio ◽  
Power Saving ◽  
Propulsive Efficiency ◽  
Engine Design ◽  
Feasible Range ◽  
Shaft Power ◽  
Cfd Analyses ◽  
The Given

Abstract The benefit of the boundary layer ingestion (BLI) is described in the perspective of the propulsion and engine development. A power saving map of the BLI engines is derived based on the correlation of the wake velocity ratio of the ingested boundary layer profile and the propulsive efficiency. The ratio of the mass flow rate between BLI and non-BLI propulsors is introduced to quantify the power saving of the BLI engine relative to a clean inlet flow engine which generates same amount of thrust. The wake recovery factor from the jet flow out of the BLI engine is employed to find an adequate sizing of the BLI engine for the given design requirement. The effects of the fan pressure ratio on the power saving are also investigated to explore the feasible range of the BLI engine design. The derived correlation is validated with CFD analyses. A numerical experiment is carried out by varying the wake velocity ratio through different BLI engines sized with respect to an influencing body. Consequently, the propulsor efficiency is quantified and presented by the saving in the actual shaft power. The efficiency penalty, pressure ratio of the BLI fan stage are correlated with the power saving and the correlation is validated through BLI2DTF and R4 fan stage CFD analyses based on rig test data.

Aerodynamic and Aeroacoustic Optimization of a Transonic Centrifugal Compressor

2014 ◽  
Author(s):  
Peng Wang ◽  
Mehrdad Zangeneh
Keyword(s):  
Pressure Ratio ◽  
Transonic Compressor ◽  
Numerical Predictions ◽  
Ansys Cfx ◽  
Transonic Centrifugal Compressor ◽  
Blade Tip ◽  
Surface Scheme ◽  
Lower Noise ◽  
Integral Surface ◽  
Good Agreement

The performance of transonic compressors can be characterized aerodynamically and aeroacoustically. In this paper, the DLR SRV2 compressor without vaned diffusers and its redesigned version are studied. The redesign strategy (Zangeneh et al. 2011 [1]) utilized the 3D inverse design and CFD analysis. Both compressors were analyzed in ANSYS CFX 11, and the computational results show that the predicted pressure-ratio and efficiency of the original compressor have good agreement with experimental results. The simulations have also revealed that the redesigned one is superior at both design and off-design points at different rotating speeds. This work applies a convective FW-H method to further investigate the noise radiation from these two compressors. As the blade tip speed is supersonic, the permeable integral surface scheme must be adopted. The flow quantities needed as the inputs to the FW-H solver were extracted from the CFD solutions. The numerical predictions of the noise SPLs at blade passing frequency and its harmonics match the experimental measurements reasonably well. It is found that the original compressor has significant variations of SPLs as the operating mass flow rate changes whereas the redesigned one has much slighter variations. At peak efficiency the redesigned compressor has a lower noise level. This study provides insights for the optimal design of a transonic compressor when good aerodynamic and aeroacoustic performance are both required.

Design, Fabrication and Analysis of an Electric Ducted Fan

2019 ◽  
Author(s):  
Parthasarathy Vasanthakumar ◽  
Jigme Tsering ◽  
Sumanth Siddhartha Suddunuri
Keyword(s):  
Rapid Development ◽  
Propulsion System ◽  
Basic Principles ◽  
Blade Element Theory ◽  
Ducted Fan ◽  
Ansys Cfx ◽  
Electric Aircraft ◽  
Feasible Option ◽  
Efficient Combustion ◽  
Battery Technology

Abstract Driven by rapid development in battery technology and increase in scope for electric air taxi vehicles, developing an efficient combustion free propulsion system to pair with an electric aircraft is crucial for future of aircraft industry. However, with current technology, ducted fan configuration engines are the only feasible option when it comes to combustion free propulsion system which are already being used in many unmanned drones and unmanned aerial vehicles. In the present work, simple design, analysis and fabrication of ducted fan is performed. Propeller fan and duct is designed using basic principles of blade element theory and momentum theory. Using the parameters from the theoretical design phase, 3D model is made and fabricated using 3D printing and assembled to fit with tolerances suitable for mounting motor. A test stand capable of measuring thrust by varying rpm is designed and built using Arduino based interface. Finally, the designed model is analyzed in Ansys CFX for thrust output using an MRF simulation.

A Comparison of Two Fan Stage Designs With Different Rotor Leading Edge Sweep

2014 ◽  
Author(s):  
John Gunaraj ◽  
David Hanson ◽  
Jeffrey Hayes ◽  
Heath Lorzel ◽  
Nick Nolcheff ◽  
...  
Keyword(s):  
Pressure Ratio ◽  
Stability Margin ◽  
Leading Edge ◽  
Flow Capacity ◽  
Numerical Predictions ◽  
Performance Trends ◽  
Ansys Cfx ◽  
Significant Difference ◽  
Total Temperature ◽  
The Individual

Two modern single-stage fans have been designed to meet the same set of performance objectives. The most significant difference between the two designs is the fan rotor leading edge sweep. The baseline rotor has a moderately aft swept leading edge while the redesigned rotor has a more complex sweep distribution, including moderate forward sweep in the tip region. Each stage consists of the fan rotor, full span stator, and split mid-frame, and is designed for a medium bypass ratio turbofan application. The stator and the mid-frame are identical for the two configurations. The primary purpose of this study is to validate the CFD methodology, in this case a steady ANSYS-CFX approach, to predict the fan stage performance at the operating point at two tested speeds and also to predict the stalling throttle condition. Numerical predictions and engine test results are presented and show good agreement. These predicted results are compared with high quality test data including thorough measurements of total pressure and total temperature at both the rotor and stator exits allowing for a detailed understanding and comparison of the individual blade row performance. The analytical model identifies the key performance trends, including an increase in flow capacity and stability margin with equivalent stage pressure ratio and efficiency for the redesigned fan relative to the baseline.

Undergraduate Gas Turbine Engine Design Using Spreadsheets and Commercial Software

2000 ◽  
Author(s):  
Kenneth W. Van Treuren ◽  
Brenda A. Haven
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Pressure Ratio ◽  
Sensitivity Study ◽  
Commercial Software ◽  
Turbine Engine ◽  
Mission Analysis ◽  
Engine Design ◽  
Student Team ◽  
Engine Cycle

A unique, three-part undergraduate gas turbine engine design project was developed to acquaint students, working in teams of two or three, with the process of engine cycle selection. The design application is a low-flying, Close Air Support (CAS) aircraft using a separate exhaust turbofan engine. Both spreadsheets and commercial software are used. The commercial software is included with the course textbook, “Elements of Gas Turbine Propulsion” by Dr Jack D. Mattingly. Using commercial software, reinforced by classroom lectures, allows the students to focus on the design decisions. The first part of the project is Mission Analysis which introduces the student teams to the design problem. A spreadsheet template is given to each student team that includes aircraft and mission profile specifications. The students must complete the spreadsheet and develop the relationships for lift, drag, thrust required, and fuel burn to calculate a useable fuel remaining at the end to the mission. The spreadsheet allows the students to obtain an average specific fuel consumption that results in 1500 lbm of fuel remaining at the end of the mission. This target value is used in the second part of the design process, on-design Parametric Cycle Analysis (PCA), as a basis for engine cycle selection. Parametric Cycle Analysis is accomplished using the program PARA.EXE. PARA.EXE generates a carpet plot of possible engine design choices by varying the compressor pressure ratio, bypass ratio, and fan pressure ratio. From these carpet plots the students must identify three possible engine cycles that meet the target value for specific fuel consumption found during the mission analysis. Tradeoffs between thrust and fuel consumption are discussed and the students are required to justify their choices for the engine cycle. The last part of the project is the off-design Engine Performance Analysis (EPA) using the program PERF.EXE. The chosen engines must fly the mission and meet the required performance and mission constraint. Based on the overall mission performance, the students narrow the field of three possible engine cycles to one. Each student team then does a sensitivity study to determine if there is an additional benefit for slight changes in the design choices. The result of this sensitivity study is the students’ final engine cycle. With this cycle, an additive drag calculation is made using the program DADD.EXE to account for losses (off-design) and these losses are then factored back into the performance spreadsheet to check the engine’s capabilities for completing the mission. The iterative nature of the design process is emphasized throughout but only one pass through the process is accomplished. Units are given in English Engineering, as that is what is required for the project. Both SI and English Engineering units are taught in the course.

An Investigation on Turbine Tip and Shroud Heat Transfer

2003 ◽  
Vol 125 (3) ◽  
pp. 513-520 ◽  
Author(s):  
Kam S. Chana ◽  
Terry V. Jones
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Experimental Investigations ◽  
Inlet Temperature ◽  
Turbine Stage ◽  
Pressure Distributions ◽  
Engine Design ◽  
Nozzle Guide

Detailed experimental investigations have been performed to measure the heat transfer and static pressure distributions on the rotor tip and rotor casing of a gas turbine stage with a shroudless rotor blade. The turbine stage was a modern high pressure Rolls-Royce aero-engine design with stage pressure ratio of 3.2 and nozzle guide vane (ngv) Reynolds number of 2.54E6. Measurements have been taken with and without inlet temperature distortion to the stage. The measurements were taken in the QinetiQ Isentropic Light Piston Facility and aerodynamic and heat transfer measurements are presented from the rotor tip and casing region. A simple two-dimensional model is presented to estimate the heat transfer rate to the rotor tip and casing region as a function of Reynolds number along the gap.

scholarly journals Performance and operability of an electrically driven propulsor

2021 ◽  
pp. 146808742110663
Author(s):  
Ibrahim Eryilmaz ◽  
Huayang Li ◽  
Vassilios Pachidis ◽  
Panagiotis Laskaridis ◽  
Zi-Qiang Zhu ◽  
...  
Keyword(s):  
Electric Motor ◽  
Electric Propulsion ◽  
Design Space ◽  
Pressure Ratio ◽  
Design Tool ◽  
Aerodynamic Design ◽  
Direct Drive ◽  
Operational Flexibility ◽  
Ducted Fan ◽  
Motor Design

This manuscript discusses the operation of an electrically driven fan for a hybrid-electric propulsion system for BAe-146 aircraft. The thrust requirement is fed into an integrated cycle and aerodynamic design tool for the sizing of a ducted fan as one of the main propulsors, podded under the wing as a replacement for a turbofan engine. The electric motor design is initiated with the torque and speed requirements and with the dimensional constraints arising from the driven fan geometry. The fan operation and aerodynamic design are derived by changing the fan pressure ratio and hub-to-tip ratio to obtain a 2-D design space. Surface-mounted permanent magnet electric motor designs are mapped on the 2-D fan design space. The design and operational flexibility of the system is investigated through three scenarios. In the first scenario, the aircraft rate of climb is changed to downsize the electric motor. In the second scenario, the electric motor rated frequency is changed to increase the power density and in the third scenario the electric motor current density is changed for the same purpose. The investigated three scenarios provide design and operational guidelines for reducing the weight of the electric motor for a direct drive application.

scholarly journals The influence of the cycloid disc bearing type on the cycloidal speed reducer efficiency

2021 ◽  
Vol 343 ◽  
pp. 01004
Author(s):  
Milan Vasic ◽  
Mirko Blagojevic ◽  
Miloš Matejic ◽  
Ileana Ioana Cofaru
Keyword(s):  
High Efficiency ◽  
Rapid Expansion ◽  
Future Research ◽  
Power Losses ◽  
Rolling Bearings ◽  
Axial Forces ◽  
Different Types ◽  
Speed Reducer ◽  
Gear Trains ◽  
Compact Design

The robotics industry has experienced a rapid expansion in the last decade. As a result, the market of speed reducers with high gear ratios, high precision and a compact design is growing rapidly. In addition to these characteristics, it is very important for gear trains to have high efficiency. Because of their compact design, cycloidal speed reducers are not exposed to axial forces, which is their important characteristic. This means that radial bearings can be used in their supports. The bearing type has significant effects not only on the design and dimensions of the cycloid speed reducer but also on its efficiency. In this paper, an analysis of power losses for different types of rolling bearings of a cycloid disc has been performed. At the end of the paper, concrete conclusions are presented as well as directions for future research.

scholarly journals The influence of flow passage geometry on the performances of a supercritical CO2 centrifugal compressor

2018 ◽  
Vol 22 (Suppl. 2) ◽  
pp. 409-418 ◽  
Author(s):  
Dong-Bo Shi ◽  
Yu-Qi Wang ◽  
Yong-Hui Xie ◽  
Di Zhang
Keyword(s):  
Centrifugal Compressor ◽  
Supercritical Co2 ◽  
Pressure Ratio ◽  
Leading Edge ◽  
Thermal Design ◽  
Original Design ◽  
Impeller Blade ◽  
Flow Passage ◽  
Ansys Cfx ◽  
Design Idea

In this paper, based on the thermodynamic design of the supercritical carbon dioxide (sCO2) centrifugal compressor, the design idea of the flow passage geometries and the method to improve the performance of the sCO2 centrifugal compressor are discussed. With the help of commercial software ANSYS CFX, the influence of the shape of the leading edge and trailing edge is studied, and the elliptical leading edge makes the pressure ratio 10.30% higher and the efficiency 3.95% higher than the square leading edge. By changing the forward-swept angle and backward-swept angle of the leading edge, the effects of aerodynamic swept shape in sCO2 centrifugal compressor are discussed. The effect of the gap between the impeller blade and diffuser blade is discussed, and the 10 mm gap makes the performance best. The pressure ratio is increased by 2.5% compared with the original design, while at the same time the efficiency is slightly improved. In summary, based on thermal design of the sCO2 centrifugal compressor, the effects of different flow geometries are analyzed in detail.

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