Criterial Analysis of Nonlinear Regimes of Transonic Flow Around the Airfoils with A Pulse-Periodic Source of Energy

2012 ◽  
Vol 7 (4) ◽  
pp. 96-106
Author(s):  
Sergey Aulchenko ◽  
Vladimir Zamuraev ◽  
Anna Kalinina
Keyword(s):  
Transonic Flow ◽  
Energy Supply ◽  
Gas Flow ◽  
Minimum Energy ◽  
Periodic Mode ◽  
Dynamic Nature ◽  
Gas Dynamic ◽  
Velocity Of Propagation ◽  
Nonlinear Regimes ◽  
Small Disturbances

The paper summarizes our data regarding the energy controlling of the transonic flow. The criterial analysis of the regimes of flow which is formed around the airfoils with an external pulse-periodic energy supply was performed. We selected four criteria, which belong to the class of criteria homochronicity. They are determined by the relations between the period of the energy supply, the rate of gas flow, the velocity of propagation of small disturbances and distances from the beginning or the end zone of energy supply to the position of the closing shock in the undisturbed flow, or the size of the zone of energy. It was shown that the conditions for the forming of the nonlinear regime can be described in terms of the entered criteria of homochronicity. We also obtained estimates for the minimum energy at which the effect of nonlinear interaction is possible, as well as the time of formation of the periodic mode. It was found that the nonlinear effect predominantly has gas-dynamic nature. It was shown that the results of numerical modeling are in agreement with the criterial estimates

scholarly journals Improving the performance of the air-cooling unit in the cooling system of a radar

2021 ◽  
Vol 2057 (1) ◽  
pp. 012004
Author(s):  
Yu A Borisov ◽  
V V Volkov-Muzilev ◽  
D A Kalashnikov ◽  
H S Khalife
Keyword(s):  
Heat Exchanger ◽  
Gas Flow ◽  
Cooling System ◽  
Experimental Studies ◽  
Air Cooling ◽  
Axial Fan ◽  
Gas Dynamic ◽  
Cooling Unit ◽  
Calculation Results ◽  
Axial Fans

Abstract The article discusses the issues of reducing the size of the cooling unit of the antenna of a radar station by improving the gas-dynamic processes occurring in the air-cooling unit. The results of the experimental studies of the gas flow in a plate-fin heat exchanger, being blown by one axial fan are presented. The feasibility of changing the number of axial fans for organizing a more uniform flow around the heat-exchange surfaces has been determined by calculation and theoretical methods. The calculation results are confirmed by experimental studies of the air flow in the segment of the heat exchanger, which is provided by a smaller fan.

The law of stabilization of the distribution of gasdynamic parameters over airfoil in a transonic flow under periodic pulsed energy supply conditions

2008 ◽  
Vol 53 (10) ◽  
pp. 533-535 ◽  
Author(s):  
V. M. Fomin ◽  
S. M. Aul’chenko ◽  
V. P. Zamuraev ◽  
A. P. Kalinina
Keyword(s):  
Transonic Flow ◽  
Energy Supply ◽  
The Law

Criterion Prediction of Changes of Shock-Wave Structure at Transonic Flow Around Airfoils with Local Impulse Energy

2014 ◽  
Vol 9 (1) ◽  
pp. 39-48
Author(s):  
Sergey Aulchenko ◽  
Vladimir Zamuraev ◽  
Anna Kalinina
Keyword(s):  
Shock Wave ◽  
Numerical Modeling ◽  
Mach Number ◽  
Pulse Energy ◽  
Transonic Flow ◽  
Energy Supply ◽  
Wave Structure ◽  
Shock Wave Structure ◽  
Wide Range ◽  
Comparison Of The Results

The results of numerical modeling of transonic streamline of profile with a local pulse energy supply were generalized in terms of criteria analysis for a wide range of parameters. Defined set of criteria allows predicting not only the degree, but the features of the flow transformation. A comparison of the results of the criteria analysis with numerical calculations of transonic streamline (Mach number M∞ = 0,85) of a symmetrical profile NASA-0012 were performed for energy supply in areas such as narrow and compact form

Numerical Modelling for Oblique Impacts With Ductile Material Particle Erosion During Cold Gas Dynamic Spray

2020 ◽  
Author(s):  
Sunday Temitope Oyinbo ◽  
Tien-Chien Jen ◽  
Samson A. Aasa
Keyword(s):  
Contact Angle ◽  
Numerical Modelling ◽  
Gas Flow ◽  
Deposition Efficiency ◽  
Ductile Material ◽  
Material Particle ◽  
Gas Dynamic ◽  
Cold Gas Dynamic Spray ◽  
Gas Dynamic Spray ◽  
Cold Gas

Abstract Another key parameter that affects the coating deposition efficiency of cold gas dynamic spray technology is the contact angle. The particle tangential sliding on the substrate at impact is due to the gas flow bow shock at a supersonic velocity which is liable for the erosion at the surface of the substrate. This study presented a finite element approach of a numerical model to investigate the profile of the deformed sprayed particles under the condition of oblique impact and the erosion mechanism for solid particle impact on ductile material during Cold Gas Dynamic spray. In the numerical modelling of cold gas dynamic spray (CGDS) by a Lagrangian approach that was developed, oblique erodent particle on the substrate at controlled contact angle (10°–90°), velocity (500 m/s) and friction coefficient (0.3) was simulated. It was discovered that in the substrate, the crater depth decreases as well as the area of contact between the substrate and the deformed particles when the contact angle increases at the same impacting conditions. The material removal and crack formation mechanism were also simulated successfully by the accumulation of residual strain that resulted in the dynamic detachment of material elements at the surface as they fail.

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