Improved Model for Small-scale Turbofan Engine Weight Estimation

Author(s):  
Evgeny Filinov ◽  
Yaroslav Ostapyuk

Author(s):  
Y. Cheng ◽  
Y. Yin ◽  
C. M. Li ◽  
W. Wu ◽  
P. P. Guo ◽  
...  

With the globalization and rapid development every filed is taking an increasing interest in physical geography and human economics. There is a surging demand for small scale world map in large formats all over the world. Further study of automated mapping technology, especially the realization of small scale production on a large scale global map, is the key of the cartographic field need to solve. In light of this, this paper adopts the improved model (with the map and data separated) in the field of the mapmaking generalization, which can separate geographic data from mapping data from maps, mainly including cross-platform symbols and automatic map-making knowledge engine. With respect to the cross-platform symbol library, the symbol and the physical symbol in the geographic information are configured at all scale levels. With respect to automatic map-making knowledge engine consists 97 types, 1086 subtypes, 21845 basic algorithm and over 2500 relevant functional modules.In order to evaluate the accuracy and visual effect of our model towards topographic maps and thematic maps, we take the world map generalization in small scale as an example. After mapping generalization process, combining and simplifying the scattered islands make the map more explicit at 1 : 2.1 billion scale, and the map features more complete and accurate. Not only it enhance the map generalization of various scales significantly, but achieve the integration among map-makings of various scales, suggesting that this model provide a reference in cartographic generalization for various scales.



2019 ◽  
Vol 5 (2) ◽  
pp. 87
Author(s):  
Mustafa Karabacak ◽  
Onder Turan


Author(s):  
Toyotaka Sonoda ◽  
Rainer Schnell ◽  
Toshiyuki Arima ◽  
Giles Endicott ◽  
Eberhard Nicke

In this paper, Reynolds effects on a modern transonic low-aspect-ratio fan rotor (Baseline) and the re-designed (optimized) rotor performance are presented with application to a small turbofan engine. The re-design has been done using an in-house numerical optimization system in Honda and the confirmation of the performance was carried out using DLR’s TRACE RANS stage code, assessed with respect to experimental data obtained from a small scale compressor rig in Honda. The baseline rotor performance is evaluated at two Reynolds number conditions, a high Reynolds condition (corresponding to a full engine scale size) and a low Reynolds number condition (corresponding to the small scale compressor rig size), using standard ISA conditions. The performance of the optimized rotor was evaluated at the low Reynolds number condition. The CFD results show significant discrepancies in the rotor efficiency (about 1% at cruise) between these two points due to the different Reynolds numbers. The optimized rotor’s efficiency is increased compared to the baseline. A unique negative curvature region close to the leading edge on the pressure surface of the optimized rotor is one of the reasons why the optimized rotor is superior to the baseline.



2020 ◽  
Vol 5 (2) ◽  
pp. 577-590 ◽  
Author(s):  
Niels Adema ◽  
Menno Kloosterman ◽  
Gerard Schepers

Abstract. Dynamic stall phenomena carry the risk of negative damping and instability in wind turbine blades. It is crucial to model these phenomena accurately to reduce inaccuracies in predicting design driving (fatigue and extreme) loads. Some of the inaccuracies in current dynamic stall models may be due to the fact that they are not properly designed for high angles of attack and that they do not specifically describe vortex shedding behaviour. The Snel second-order dynamic stall model attempts to explicitly model unsteady vortex shedding. This model could therefore be a valuable addition to a turbine design software such as Bladed. In this paper the model has been validated with oscillating aerofoil experiments, and improvements have been proposed for reducing inaccuracies. The proposed changes led to an overall reduction in error between the model and experimental data. Furthermore the vibration frequency prediction improved significantly. The improved model has been implemented in Bladed and tested against small-scale turbine experiments at parked conditions. At high angles of attack the model looks promising for reducing mismatches between predicted and measured (fatigue and extreme) loading, leading to possible lower safety factors for design and more cost-efficient designs for future wind turbines.



2018 ◽  
Vol 220 ◽  
pp. 03007
Author(s):  
Andrey Tkachenko ◽  
Evgeny Filinovaroslav Ostapyuk ◽  
Viktor Rybakov ◽  
Daria Kolmakova

The paper describes the method of selecting the working process parameters of a family of small-scale gas turbine engines (GTE) with common core. As an example, the thermodynamic design of a family of small-scale gas turbine engines (SGTE) with common core was carried out. The engine family includes a small-scale turbojet engine (STJE) and a gas turbine plant (GTP), which electric generator is driven by power turbine. The selection of rational values for the working process parameters of STJE and GTP was carried out in CAE system ASTRA on the basis of nonlinear optimization of these parameters, taking into account functional and parametric constraints. The quantitative results of deterioration in the performance of the engines of the family with common core are obtained in comparison with the engines with the optimum core for each type. However, the advanced creation of a common core can reduce the cost and timing of the engine creation, ensure its higher reliability (due to the development of the base common core) and reduce the cost of its production. The method of selecting the parameters of the working process of the GTE family with common core presents the solution to more complex problems, such as the possibility of developing a family consisting of five engines: a turbojet engine, turbofan engine, turbofan engine with a complex cycle, GTE with power turbine (GTE-PT), GTE-PT with recovery.



2018 ◽  
Vol 220 ◽  
pp. 03012
Author(s):  
Venedikt Kuz’michev ◽  
Ilia Krupenich ◽  
Evgeny Filinov ◽  
Yaroslav Ostapyuk

Accurate mathematical models for turbofan engine weight estimation are necessary requirement for optimization of the working process parameters at the initial design stage. Open-access publications provide necessary information on eight models that may be used at this design stage. Information on 77 modern turbofan engines was gathered using the available sources: publications, official websites, reference books etc. Data gaps were filled using the mathematical model identification. Gathered data cover wide range of working process parameters, thrust levels and air flow rates and was used to assess the accuracy of the abovementioned weight models. Only four models (Torenbeek, Svoboda, Raymer, Kuz’michev) provide adequate accuracy. Kuz’michev model uses the highest number of input parameters and provide the most precise results, although it must be noted that no correlation between the number of input parameters and accuracy was determined in general.



2013 ◽  
Vol 392 ◽  
pp. 667-671 ◽  
Author(s):  
Xiao Jing Yang ◽  
Fang Yao ◽  
Zhi Gang Li ◽  
Xue Bo Feng

When the relay contacts are switched on the load circuit, contact pairs on-state directly reflects the relays reliability, and it also indirectly reflects machine performance of the relay. Therefore, the static contact resistance is one of the key features of the relays state estimation and failure warning. However, the contact resistance of the relay contact is uncertainty characteristics, small-scale sequence trend model is difficult to obtain an ideal prediction performance, and therefore grey model which based on small-scale sequence for prediction of electrical contact reliability of the relay is drawn on. Using the static contact resistance measurement value of the relay contact resistance as training samples to set up GM (1, 1) model and obtaining development grey numberaand endogenous control grey numberbby least square method, so as to get differential equation of original datas predicted value and then forecast the original data. In order to improve the prediction accuracy and weaken the influence of randomness, sliding smoothing formula to the original data is used to get improved prediction model. By comparing the difference between the accuracy of improved model and not improved model, it concludes that the improved model has possibility and accuracy higher.



2019 ◽  
Vol 5 (2) ◽  
pp. 87
Author(s):  
Mustafa Karabacak ◽  
Onder Turan


2019 ◽  
Author(s):  
Niels Adema ◽  
Menno Kloosterman ◽  
Gerard Schepers

Abstract. Dynamic stall phenomena bring risk for negative damping and instability in wind turbine blades. It is crucial to model these phenomena accurately to reduce inaccuracies in predicting design driving (fatigue) loads. Inaccuracies in current dynamic stall models may be due to the facts that they are not properly designed for high angles of attack, and that they do not specifically describe vortex shedding behaviour. The Snel second order dynamic stall model attempts to explicitly model unsteady vortex shedding. This model could therefore be a valuable addition to DNV GL's turbine design software Bladed. In this thesis the model has been validated with oscillating airfoil experiments and improvements have been proposed for reducing inaccuracies. The proposed changes led to an overall reduction in error between the model and experimental data. Furthermore the vibration frequency prediction improved significantly. The improved model has been implemented in Bladed and tested against small scale turbine experiments at parked conditions. At high angles of attack the model looks promising for reducing mismatches between predicated and measured (fatigue) loading. Leading to possible lower safety factors for design and more cost efficient designs for future wind turbines.



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