scholarly journals Experimental study of the adiabatic wall temperature of a cylinder in a supersonic cross flow

2021 ◽  
Vol 2039 (1) ◽  
pp. 012029
Author(s):  
S S Popovich ◽  
N A Kiselev ◽  
A G Zditovets ◽  
Y A Vinogradov
Keyword(s):  
Experimental Study ◽  
Wall Temperature ◽  
High Speed ◽  
Cross Flow ◽  
Maximum Temperature ◽  
Thermal Imager ◽  
State University ◽  
Adiabatic Wall ◽  
Speed Flow ◽  
Total Temperature

Abstract The results of an experimental study of the adiabatic wall temperature for a supersonic air flow across the cylinder are presented. The temperature was measured contactlessly using an InfraTEC ImageIR 8855 thermal imager through a ZnSe infrared illuminator. The freestream Mach number was 3.0, input flow total temperature was 295 K, and the total pressure 615 kPa. The Reynolds number calculated from the cylinder diameter (30 mm) was about 106. It is shown that it is possible in principle to determine the high-speed flow total temperature by defining the maximum temperature of a cylindrical probe at the front critical point. Thermograms of the wall temperature distribution along the profile of the cylinder were obtained. The research was performed at the experimental facilities of the Institute of Mechanics of Lomonosov Moscow State University.

scholarly journals Numerical and experimental study of pyrophoric activated metal Mg surface combustion characteristics

2018 ◽  
Vol 5 (5) ◽  
pp. 172064
Author(s):  
Hesong Huang ◽  
Zhongxiang Tong ◽  
Chaozhe Wang ◽  
Biao Wang
Keyword(s):  
Temperature Distribution ◽  
Heat Balance ◽  
High Speed ◽  
Difficult Problem ◽  
Combustion Mechanism ◽  
Thermal Imager ◽  
Balance Equations ◽  
Adiabatic Wall ◽  
The Heat Balance ◽  
Infrared Thermal Imager

The combustion of multi-hole pyrophoric activated metal is solid combustion and the combustion mechanism is quite complex, which is a difficult problem to be solved. Once the pyrophoric activated metal is exposed to air, the oxygen diffuses to the interior of the activated metal within plenty of holes and reacts with it, which enlarges the contact area with oxygen. Consequently, the whole combustion is vigorous and the temperature rises rapidly. To study the combustion mechanism of the chaff, the surface heat balance equation is established in this work by taking Mg as the activated metal. To solve this equation, the chaff adiabatic wall temperature distribution is computed by computational fluid dynamics in the presence of high-speed airflow. Then, the chaff surface temperature distribution is obtained by solving the heat balance equations. Finally, numerical and experimental results obtained via an infrared thermal imager are compared to demonstrate the effectiveness of the established equation.

Film Cooling Efficiency in the Supersonic Flow With Foreign Gas Injection

2010 ◽  
Author(s):  
A. G. Zditovets ◽  
A. I. Leontiev ◽  
U. A. Vinogradov ◽  
M. M. Strongin ◽  
A. A. Titov
Keyword(s):  
Wall Temperature ◽  
Film Cooling ◽  
Gas Injection ◽  
Supersonic Boundary Layer ◽  
Low Flow ◽  
Coolant Temperature ◽  
State University ◽  
Adiabatic Wall ◽  
Supersonic Wind Tunnel ◽  
Experimental Researches

Numerical investigation (A.I.Leontiev, V.G.Lushchik, A.E.Jakubenko «PARADOXES OF HEAT TRANSFER ON A PERMEABLE WALL») shows that adiabatic wall temperature in the region of the gas film may be lower than the injected gas (coolant) temperature. It occurs in case of foreign light-gas injection and it does not occur in case of uniform gas injection under the same conditions. This paper is devoted to the experimental investigation of this conclusion. Experimental researches have been conducted in the low flow-rate supersonic wind tunnel (Mach number of 3) located in the Institute of Mechanics of the Moscow State University. Argon was used as a primary stream, helium and argon as coolant. The coolant was blown in through the porous permeable part of a model and injected into the supersonic boundary layer. The surface temperature of the model was gained with use of the infrared scanning device ThermaCAM SC 3000. As a result following data have been obtained. It is shown in particular that the adiabatic wall temperature in the region of the gas film may be lower than the injected gas (coolant) temperature. This effect does not take place in case of uniform (air-air, argon-argon etc.) gas injection, for this effect is especially essential for gas mixtures with low values of the Prandtl number.

An Experimental Study on High Speed Flow in Microtube

2002 ◽  
Vol 2002 (0) ◽  
pp. 225-226
Author(s):  
Kazuo HARA ◽  
Haruo INOUE ◽  
Hiroyuki NAKAMURA ◽  
Masahiro INOUE
Keyword(s):  
Experimental Study ◽  
High Speed ◽  
High Speed Flow ◽  
Speed Flow

scholarly journals Development of Gas Dynamic Probe for High Total Temperature Measurement in High Speed Flow

2017 ◽  
Vol 234 ◽  
pp. 012004
Author(s):  
Tahzeeb Hassan Danish ◽  
Yash Mistry ◽  
K Sathiyamoorthy ◽  
J Srinivas ◽  
P Pratheesh Kumar
Keyword(s):  
Temperature Measurement ◽  
High Speed ◽  
High Speed Flow ◽  
Gas Dynamic ◽  
Speed Flow ◽  
Total Temperature

scholarly journals Experimental Study of Adaptive Control of High-Speed Flow-Induced Cavity Oscillations

2011 ◽  
Vol 6 (5) ◽  
pp. 701-716 ◽  
Author(s):  
Hidemi TAKAHASHI ◽  
Fei LIU ◽  
Miguel PALAVICCINI ◽  
Matias OYARZUN ◽  
John GRIFFIN ◽  
...  
Keyword(s):  
Experimental Study ◽  
Adaptive Control ◽  
High Speed ◽  
High Speed Flow ◽  
Speed Flow

Numerical and experimental study of heat transfer in gas-solid flow: Particle cooling

2012 ◽  
Vol 3 (1) ◽  
pp. 21-29
Author(s):  
S. M. El-Behery ◽  
W. A. El-Askary ◽  
M. H. Hamed ◽  
K. A. Ibrahim
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Experimental Study ◽  
High Speed ◽  
Solid Phase ◽  
Ideal Gas ◽  
Particle Rotation ◽  
Two Phase ◽  
Solid Flow ◽  
Speed Flow

Abstract Heat transfer in gas-solid two-phase flow is investigated numerically and experimentally. The numerical computations are carried out using four-way coupling Eulerian-Lagrangian approach. The effects of particle rotation and lift forces are included in the model. The gas-phase turbulence is modeled via low Reynolds number k-ε turbulence models. The SIMPLE algorithm is extended to take the effect of compressibility into account. The experimental study is performed using crushed limestone to simulate the solid phase. The effects of Reynolds numbers, particles size and temperature on the pressure drop and the temperature of the phases are investigated. The model predictions are found to be in a good agreement with available experimental data for high speed gas-solid flow and present experimental data for low speed flow. The present results indicate that heat transfer in gas solid flow can be modeled using ideal gas incompressible flow model at low conveying speed, while for high speed flow, a full compressible model should be used.

Heat Transfer and Forces for Free-Molecule Flow on a Concave Cylindrical Surface

1964 ◽  
Vol 86 (1) ◽  
pp. 1-9 ◽  
Author(s):  
E. M. Sparrow ◽  
V. K. Jonsson ◽  
T. S. Lundgren ◽  
T. S. Chen
Keyword(s):  
Heat Transfer ◽  
Wall Temperature ◽  
Cylindrical Surface ◽  
High Speed ◽  
Angle Of Attack ◽  
Accommodation Coefficient ◽  
Free Molecule ◽  
Adiabatic Wall ◽  
The Difference ◽  
Molecule Flow

An analysis has been carried out to determine the local and overall heat-transfer rates, the adiabatic wall temperature, and the forces exerted when a high-speed, free-molecule flow is incident on a concave cylindrical surface. The flow may impinge on the surface at an arbitrary angle of attack. Additionally, the thermal accommodation coefficient may be arbitrary, and the degree of concavity of the surface may be varied at will from a semicircular cross section to a relatively flat circular arc. The concavity causes molecules to interreflect back and forth between surface elements. Even with the interreflections, the heat-transfer rate continues to depend linearly on the difference between the wall temperature and the adiabatic wall temperature. The interreflections are found to have a greater effect on both the heat transfer and the force results as the accommodation co-efficient decreases and as the degree of concavity and the angle of attack increase.

Numerical Study of Shear-Induced Heating in High-Speed Nozzle Flow of Liquid Monopropellant

1998 ◽  
Vol 120 (1) ◽  
pp. 58-64 ◽  
Author(s):  
X. Shi ◽  
O. M. Knio ◽  
J. Katz
Keyword(s):  
Wall Temperature ◽  
High Speed ◽  
Numerical Study ◽  
Small Diameter ◽  
Numerical Schemes ◽  
Axisymmetric Nozzle ◽  
Wall Boundary Layer ◽  
Speed Flow ◽  
Prandtl Numbers ◽  
Temperature Dependent Properties

A numerical study is performed which focuses on peak temperatures experienced by a liquid monopropellant during high-speed injection in a small-diameter nozzle. Attention is focused on short-duration injection during which the nozzle wall boundary layer is predominantly laminar. An unsteady ID analysis of the temperature distribution associated with sudden fluid acceleration over a flat insulated boundary is first conducted. Expressions are provided which relate the normalized peak wall temperature to the prevailing Eckert and Prandtl numbers. Results reveal a quadratic dependence of the normalized wall temperature on impulse velocity, and a nonlinear variation with Prandtl number. Next, simulation of high-speed flow in an axisymmetric nozzle is performed. The numerical schemes are based on finite-difference discretization of a vorticity-based formulation of the mass, momentum, and energy conservation equations. Implementation of the numerical schemes to flow of LP 1846 in a 4 mm diameter nozzle indicates that preignition is likely to occur for velocities higher than 200 m/s. The effects of wall heat transfer and temperature-dependent properties are also discussed.

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