scholarly journals About the flow aerodynamic model with engines over the wing

2021 ◽  
Author(s):  
N. N. Bragin ◽  
A. L. Bolsunovsky ◽  
N. P. Buzoverya ◽  
N. A. Pushchin ◽  
S. I. Skomorokhov ◽  
...  
Keyword(s):  
AIAA Journal ◽  
2002 ◽  
Vol 40 ◽  
pp. 1187-1196
Author(s):  
J.-N. Juang ◽  
D. Kholodar ◽  
E. H. Dowell

1997 ◽  
Vol 75 (7) ◽  
pp. 1176-1183 ◽  
Author(s):  
Horacio de la Cueva ◽  
Robert W. Blake

Aerodynamic power equations predict optimal speeds at which birds ought to fly if they are to maximize time spent in the air on a given energy store (minimum power speed, Vmp), distance covered using a given amount of fuel (maximum range speed, Vmr), and rate of delivering food to the chicks in the nest (Vnest), or maximize the daily energy balance (VDBAL). With the aerodynamic model employed, these speeds are 5.3, 7.0, 7.9, and 8.9 m∙s−1, respectively, for the Barn Swallow, Hirundo rustica. A comparison of the predicted flight speed with both the mean and median flight speeds (8 m∙s−1 in both cases; n = 821) recorded with Doppler radar indicates that Barn Swallows fly at speeds not significantly different from Vnest. The true sample size was unknown, and realistic sample sizes are drawn with bootstrap procedures and compared with those given by the number of measurements (821); no significant differences were found. To test the model, energy requirements for growth, prey density, and time spent foraging were varied independently in a sensitivity analysis. Large but realistic changes in these three variables do not contradict the model and predict speeds within the range measured in the field.


2019 ◽  
Vol 52 (9-10) ◽  
pp. 1382-1393 ◽  
Author(s):  
Xiang Zhang ◽  
Yonghua Lu ◽  
Yang Li ◽  
Chi Zhang ◽  
Rui Wang

In order to analyze the response characteristics of the solenoid valve in depth, the flow field of the solenoid valve is analyzed by means of the computational fluid dynamics, and the aerodynamic parameters that are difficult to be obtained by the traditional methods are obtained with software FLUENT. We also set up the mathematical model of the solenoid valve, including the aerodynamic model, the circuit model, the magnetic circuit model and the mechanical motion model. The calculation is completed in the Simulink, and the results of the calculation are analyzed. A set of the solenoid valve response characteristic test system is built, and the response characteristic parameters such as response time and maximum action frequency of the solenoid valve are tested. The experimental results are verified by comparing them with the simulation results. The final result shows that the response characteristics are basically irrelevant to the action frequency at a suitable working frequency. The open switching time of the solenoid valve decreases with the increase in the inlet pressure and the driving voltage and increases with the increase in the number of coil turns. The close switching time increases with the increase in the inlet pressure, the driving voltage and the number of coil turns.


2019 ◽  
Vol 95 ◽  
pp. 105511 ◽  
Author(s):  
Halil Kaya ◽  
Hakan Tiftikçi ◽  
Ümit Kutluay ◽  
Evren Sakarya

2019 ◽  
Vol 11 (01) ◽  
pp. 1950008
Author(s):  
Binwen Wang ◽  
Xueling Fan

Flutter is an aeroelastic phenomenon that may cause severe damage to aircraft. Traditional flutter evaluation methods have many disadvantages (e.g., complex, costly and time-consuming) which could be overcome by ground flutter test technique. In this study, an unsteady aerodynamic model is obtained using computational fluid dynamics (CFD) code according to the procedure of frequency domain aerodynamic calculation. Then, the genetic algorithm (GA) method is adopted to optimize interpolation points for both excitation and response. Furthermore, the minimum-state method is utilized for rational fitting so as to establish an aerodynamic model in time domain. The aerodynamic force is simulated through exciters and the precision of simulation is guaranteed by multi-input and multi-output robust controller. Finally, ground flutter simulation test system is employed to acquire the flutter boundary through response under a range of air speeds. A good agreement is observed for both velocity and frequency of flutter between the test and modeling results.


2017 ◽  
Vol 7 (2) ◽  
pp. 159 ◽  
Author(s):  
Yu Fan ◽  
Fang Lu ◽  
Wuxuan Zhu ◽  
Guangzhou Bai ◽  
Liang Yan

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