Characteristics of gas-driven fan propulsion system for fixed-wing vertical take-off and landing aircraft

2021 ◽  
pp. 095441002110251
Author(s):  
Yang Zhou ◽  
Guoping Huang ◽  
Chen Xia ◽  
Yuanzhao Zhu
Keyword(s):  
Preliminary Analysis ◽  
Weight Ratio ◽  
Propulsion System ◽  
Development Cost ◽  
Ratio Requirement ◽  
Guide Vanes ◽  
The Core ◽  
Ducted Fan ◽  
Vtol Aircraft ◽  
Operation Characteristics

As a propulsion system for vertical take-off and landing (VTOL) aircraft, the gas-driven fan propulsion system has received some attention in recent years due to its simple mechanical structure and good performance. During the operation of the propulsion system, the core turbofan exhaust is directed to the tip turbine to drive the ducted fan to obtain thrust, and the louvered vector exhaust device is used to achieve lift/thrust switching. However, due to the linkage characteristics of the guide vanes of the exhaust device, the exhaust area will gradually change with the deflection of the guide vanes. This may cause uncertain effects on the system. Besides, considering the development cost of the propulsion system, it is necessary to clarify whether the core turbofan needs to be redesigned based on the characteristics of the system. Further, the transitional performance (VTOL to flight) of the propulsion system also needs to be studied. To this end, this study established an overall model of the gas-driven fan propulsion system combined with the characteristics of the core turbofan to analyze these problems. The results indicate that the louvered vector exhaust device can well match the gas-driven fan propulsion system. And when the propulsion system is composed, the gas-driven fan will not significantly affect the operation characteristics of the core turbofan. Besides, the preliminary analysis shows that the gas-driven fan propulsion system can meet the power requirements of the transition state of the fixed-wing VTOL aircraft. And the characteristics of the propulsion system may make the take-off thrust-weight ratio requirement of the fixed-wing VTOL aircraft be as low as 1.1.

Analysis of Advanced PWR Loading Schemes for Transuranic Incineration in Thorium

2013 ◽  
Author(s):  
Benjamin A. Lindley ◽  
N. Zara Zainuddin ◽  
Fausto Franceschini ◽  
Geoffrey T. Parks
Keyword(s):  
Temperature Coefficient ◽  
Preliminary Analysis ◽  
Detrimental Effect ◽  
Spatial Separation ◽  
Trade Off ◽  
The Core ◽  
Positive Reactivity ◽  
Fuel Pin ◽  
Control Rods

It is difficult to perform multiple recycle of transuranic (TRU) isotopes in PWRs as the moderator temperature coefficient (MTC) tends to become positive after a few recycles and the core may have positive reactivity when fully voided. Due to the favorable impact on the MTC and void coefficient fostered by use of thorium (Th), the possibility of performing Th-TRU multiple-recycle in reduced-moderation PWRs (RMPWRs) is under consideration. The simplest way to reduce the moderation in a PWR is to increase the fuel pin diameter. This configuration improves the trade-off between achievable burn-up and MTC, but is ultimately limited by thermal-hydraulic constraints. Heterogeneous recycle with the bred uranium (U3) and the TRU are arranged in separate pins was found to be neutronically preferable to a homogeneous configuration. Spatial separation also enables the U3 and TRU to be refueled on different batch schemes. These techniques allow satisfactory discharge burn-up while ensuring negative MTC and fully voided reactivity, with the pin diameter of a standard PWR increased from 9.5 mm to 11 mm. Reactivity control is a key challenge due to the reduced worth of neutron absorbers and their detrimental effect on the void coefficients, especially when diluted, as is the case for soluble boron. It seems necessary to control the core using control rods to keep the fully voided reactivity negative. A preliminary analysis indicates that this is feasible.

An adaptive Dendrite-HDMR metamodeling technique for high dimensional problems

2022 ◽  
pp. 1-38
Author(s):  
Qi Zhang ◽  
Yizhong Wu ◽  
Li Lu ◽  
Ping Qiao
Keyword(s):  
Adaptive Sampling ◽  
Clustering Algorithm ◽  
Learning Algorithm ◽  
Weight Ratio ◽  
Propulsion System ◽  
High Dimensional ◽  
High Dimensional Model Representation ◽  
K Nearest Neighbor ◽  
Metamodeling Technique ◽  
Explicit Expressions

Abstract High dimensional model representation (HDMR), decomposing the high-dimensional problem into summands of different order component terms, has been widely researched to work out the dilemma of “curse-of-dimensionality” when using surrogate techniques to approximate high-dimensional problems in engineering design. However, the available one-metamodel-based HDMRs usually encounter the predicament of prediction uncertainty, while current multi-metamodels-based HDMRs cannot provide simple explicit expressions for black-box problems, and have high computational complexity in terms of constructing the model by the explored points and predicting the responses of unobserved locations. Therefore, aimed at such problems, a new stand-alone HDMR metamodeling technique, termed as Dendrite-HDMR, is proposed in this study based on the hierarchical Cut-HDMR and the white-box machine learning algorithm, Dendrite Net. The proposed Dendrite-HDMR not only provides succinct and explicit expressions in the form of Taylor expansion, but also has relatively higher accuracy and stronger stability for most mathematical functions than other classical HDMRs with the assistance of the proposed adaptive sampling strategy, named KKMC, in which k-means clustering algorithm, k-Nearest Neighbor classification algorithm and the maximum curvature information of the provided expression are utilized to sample new points to refine the model. Finally, the Dendrite-HDMR technique is applied to solve the design optimization problem of the solid launch vehicle propulsion system with the purpose of improving the impulse-weight ratio, which represents the design level of the propulsion system.

Ice Crystal Icing Investigation on a Honeywell Uncertified Research Engine in an Altitude Simulation Icing Facility

2020 ◽  
Author(s):  
Ashlie B. Flegel
Keyword(s):  
Particle Size ◽  
Guide Vane ◽  
Leading Edge ◽  
Inlet Guide Vane ◽  
Inlet Temperature ◽  
Ice Crystal ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
The Core ◽  
Break Up

Abstract A Honeywell Uncertified Research Engine was exposed to various ice crystal conditions in the NASA Glenn Propulsion Systems Laboratory. Simulations using NASA’s 1D Icing Risk Analysis tool were used to determine potential inlet conditions that could lead to ice crystal accretion along the inlet of the core flowpath and into the high pressure compressor. These conditions were simulated in the facility to develop baseline conditions. Parameters were then varied to move or change accretion characteristics. Data were acquired at altitudes varying from 5 kft to 45 kft, at nominal ice particle Median Volumetric Diameters from 20 μm to 100 μm, and total water contents of 1 g/m3 to 12 g/m3. Engine and flight parameters such as fan speed, Mach number, and inlet temperature were also varied. The engine was instrumented with total temperature and pressure probes. Static pressure taps were installed at the leading edge of the fan stator, front frame hub, the shroud of the inlet guide vane, and first two rotors. Metal temperatures were acquired for the inlet guide vane and vane stators 1–2. In-situ measurements of the particle size distribution were acquired three meters upstream of the engine forward fan flange and one meter downstream of the fan in the bypass in order to study particle break-up behavior. Cameras were installed in the engine to capture ice accretions at the leading edge of the fan stator, splitter lip, and inlet guide vane. Additional measurements acquired but not discussed in this paper include: high speed pressure transducers installed at the trailing edge of the first stage rotor and light extinction probes used to acquire particle concentrations at the fan exit stator plane and at the inlet to the core and bypass. The goal of this study was to understand the key parameters of accretion, acquire particle break-up data aft of the fan, and generate a unique icing dataset for model and tool development. The work described in this paper focuses on the effect of particle break-up. It was found that there was significant particle break-up downstream of the fan in the bypass, especially with larger initial particle sizes. The metal temperatures on the inlet guide vanes and stators show a temperature increase with increasing particle size. Accretion behavior observed was very similar at the fan stator and splitter lip across all test cases. However at the inlet guide vanes, the accretion decreased with increasing particle size.

scholarly journals CFD Study of an Annular-Ducted Fan Lift System for VTOL Aircraft

Aerospace ◽  
2015 ◽  
Vol 2 (4) ◽  
pp. 555-580 ◽  
Author(s):  
Yun Jiang ◽  
Bo Zhang ◽  
Tao Huang
Keyword(s):  
Ducted Fan ◽  
Vtol Aircraft

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.

scholarly journals Measurements of CO2 and CH4 concentrations in air in a polar ice core

1993 ◽  
Vol 39 (132) ◽  
pp. 209-215 ◽  
Author(s):  
Takakiyo Nakazawa ◽  
Toshinobu Machida ◽  
Kenji Esumi ◽  
Masayuki Tanaka ◽  
Yoshiyuki Fujii ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Preliminary Analysis ◽  
Extraction Efficiency ◽  
Ice Core ◽  
Fine Powder ◽  
Glacial Period ◽  
Polar Ice ◽  
The Core ◽  
Precise Analysis ◽  
Better Than

AbstractDry and wet air-extraction systems and precise analysis systems of the CO2and CH4concentrations for a polar ice core were developed to reconstruct their ancient levels. A dry-extraction system was capable of crushing an ice sample of 1000 g into fine powder within 2 min, and its air-extraction efficiency was found to be 98%. The CO2and CH4concentrations of extracted air were determined using gas chromatography with a flame-ionized detector. The overall precision of our measurements, including air extraction, was estimated to be better than ± 1 ppmv for CO2and + 10 ppbv for CH4. Preliminary analysis of the ice core drilled at Mizuho Station, Antarctica, showed that the CO2and CH4concentrations at 3340–3700 year BP were about 280 ppmv and 700ppbv, respectively. The Yamato core drilled at the terminus of the glacial flow near the Yamato Mountains, Antarctica, yielded concentrations of 230–240 ppmv for CO2and 520–550 ppbv for CH4, suggesting that the core had formed during the glacial period.

scholarly journals Quantification of uncertainty in rapid estimation of earthquake fatalities based on scenario analysis

2018 ◽  
Author(s):  
Xiaoxue Zhang ◽  
Hanping Zhao ◽  
Fangping Wang ◽  
Zezheng Yan ◽  
Sida Cai ◽  
...  
Keyword(s):  
Emergency Response ◽  
Preliminary Analysis ◽  
Accurate Estimation ◽  
Earthquake Parameters ◽  
Rapid Estimation ◽  
Factors Affecting ◽  
The Core ◽  
Comparison Results ◽  
Emergency Scenarios ◽  
Earthquake Fatalities

Abstract. The rapid estimation of earthquake fatalities using earthquake parameters is the core basis for emergency response. However, there are numerous factors affecting earthquake fatalities, and it is impossible to obtain an accurate estimation result. The key to solve this problem is quantifying the uncertainty. In this paper, we proposed a new method to estimate earthquake fatalities and quantify the uncertainty based on basic earthquake emergency scenarios. The accuracy of the model is verified by earthquake that occurred during recent year. The preliminary analysis and comparison results show that the model is more effective and reasonable and can also provide a theoretical basis for post-earthquake emergency response.

scholarly journals Design of a Cogeneration Hybrid Propulsion System for Commuter Aircrafts With Thermal Recovery

2015 ◽  
Author(s):  
Michele Trancossi
Keyword(s):  
Heat Recovery ◽  
Ghg Emissions ◽  
System Optimization ◽  
Thermal Recovery ◽  
Propulsion System ◽  
Hybrid Propulsion ◽  
Ducted Fan ◽  
Constructal Law ◽  
Cogeneration System ◽  
Effective Design

This paper approaches the argument of cogeneration in aircraft propulsion. It presents an effective design of a cogeneration system with thrust augmentation by heat recovery for aeronautic propulsion which can be installed inside an electrical ducted fan unit. The system optimization is based on constructal law. Energy comparison against potential competitors is produced together with an analysis in terms of GHG emissions.

Sign in / Sign up

Export Citation Format

Share Document