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.

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 The effect of wall cooling on a compressible turbulent boundary layer

1974 ◽  
Vol 66 (3) ◽  
pp. 507-528 ◽  
Author(s):  
R. L. Gran ◽  
J. E. Lewis ◽  
T. Kubota
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Wall Temperature ◽  
High Speed ◽  
Thermal Boundary Layer ◽  
Pressure Gradients ◽  
Wall Boundary Layer ◽  
Free Stream Mach Number ◽  
High Speed Data ◽  
Good Agreement

Experimental results are presented for two turbulent boundary-layer experiments conducted at a free-stream Mach number of 4 with wall cooling. The first experiment examines a constant-temperature cold-wall boundary layer subjected to adverse and favourable pressure gradients. It is shown that the boundary-layer data display good agreement with Coles’ general composite boundary-layer profile using Van Driest's transformation. Further, the pressuregradient parameter βK found in previous studies to correlate adiabatic highspeed data with low-speed data also correlates the present cooled-wall high-speed data. The second experiment treats the response of a constant-pressure highspeed boundary layer to a near step change in wall temperature. It is found that the growth rate of the thermal boundary layer within the existing turbulent boundary layer varies considerably depending upon the direction of the wall temperature change. For the case of an initially cooled boundary layer flowing onto a wall near the recovery temperature, it is found that δT ∼ x whereas the case of an adiabatic boundary layer flowing onto a cooled wall gives δT ∼ x½. The apparent origin of the thermal boundary layer also changes considerably, which is accounted for by the variation in sublayer thicknesses and growth rates within the sublayer.

Numerical Study of Classification of Ultrafine Particles in a Gas-Solid Field of Elbow-Jet Classifier

2005 ◽  
Author(s):  
Shibin Liang
Keyword(s):  
Flow Field ◽  
Ultrafine Particles ◽  
High Speed ◽  
Numerical Study ◽  
Experimental Results ◽  
Speed Flow ◽  
Fluent Software ◽  
Air Classifier ◽  
Different Diameters

Computational fluid dynamics (CFD) is applied to develop a novel submicron air classifier. Based on different inner structure sizes and positions in the elbow-jet classifier, the two-dimensional air flow field has been simulated by the Fluent software. The Coanda-effect plays a paramount role in the separation of ultrafine particles in the high-speed flow field of the elbow-jet classifier. The effects on the features of the Coanda element, i.e. a half-cylinder, have been analyzed and discussed. The trajectories of moving particles with different diameters in the channels and chambers of the classifier have been calculated under the velocity field simulation results obtained by the CFD analysis. The cut sizes of three products at the related outlets of the classifier are obtained based on the trajectories calculation of the particles and compared with the corresponding experimental results. The ground/classified experiment has been conducted by using the products outlet of a vortex jet mill as the particles feed of the elbow-jet classifier. The experimental results show that the external classifier for the vortex jet mill improves the classification of the mill significantly. The combination of the vortex jet mill with the external classifier provides a new choice of the grinding equipment for the multiple size products of fine/medium/coarse powders. A centrifugal channel has been added between the vortex jet mill and the elbow-jet classifier to improve the performance of the air classifier. Both numerical and experimental results show that the pre-distributed feed powders at the exit of the centrifugal channel have a strong effect on the fine powders separation and a less effect on the coarse powders separation.

Transonic buffet of a space launcher aileron: Fanno and Rayleigh flows analogies

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nicolas Gourdain ◽  
Jéromine Dumon ◽  
Yannick Bury ◽  
Pascal Molton
Keyword(s):  
Wall Temperature ◽  
High Speed ◽  
Numerical Study ◽  
Navier Stokes ◽  
Content Type ◽  
Eddy Simulation ◽  
Flow Coupling ◽  
Numerical Predictions ◽  
Large Eddy ◽  
Transonic Buffet

Purpose The transonic buffet is a complex aerodynamics phenomenon that imposes severe constraints on the design of high-speed vehicles, including for aircraft and space launchers. The origin of buffet is still debated in the literature, and the control of this phenomenon remains difficult. This paper aims to propose an original scenario to explain the origin of buffet, which in turn opens promising perspectives for its alleviation and attenuation. Design/methodology/approach This work relies on the use of numerical simulations, with the idea to reproduce the buffet phenomenon in a transonic aileron designed for small space launchers. Two numerical approaches are tested: unsteady Reynolds averaged Navier–Stokes (URANS) and large-eddy simulation (LES). The numerical predictions are first validated against available experimental data, before to be analysed in detail to identify the origin of buffet on the studied configuration. A complementary numerical study is then conducted to assess the possibility to delay the onset of buffet. Findings The buffet control strategy is based on wall cooling. By adequately choosing the wall temperature, this work shows that it is feasible to delay the emergence of buffet. More precisely, this paper highlights the crucial role of the subsonic flow inside the boundary layer, showing the existence of upstream travelling pressure waves that are responsible for the flow coupling between both sides of the airfoil, at the origin of the buffet phenomenon. Originality/value This paper proposes a new scenario to explain the origin of buffet, based on the use of a Fanno and Rayleigh flow analogies. This approach is used to design a control solution based on a modification of the wall temperature, showing very promising results.

Simulation the formation process of boiling water flow during depressurization of a high pressure vessel using OpenFoam open source

2017 ◽  
Vol 12 (2) ◽  
pp. 169-173 ◽  
Author(s):  
R.Kh. Bolotnova ◽  
V.A. Korobchinskaya
Keyword(s):  
Open Source ◽  
High Speed ◽  
Numerical Study ◽  
Mass Conservation ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Speed Flow ◽  
Initial Stage ◽  
Calculation Results ◽  
Water Outflow

A numerical study of the initial stage of water outflow process through a thin nozzle from a supercritical state in a two-dimensional axisymmetric setting is performed using the OpenFOAM software open source with the sonicFoam solver. The mathematical model of sonicFoam solver includes the equation of mass conservation, Navier-Stokes equation, internal energy conservation and equation of state of water vapor in the form of a perfect gas. Visualization of calculation results was carried out by the ParaView graphic platform. The features of supersonic high-speed flow regime in a jet accompanied by the formation of a hollow jet in a form close to parabolic are investigated.

Visualization of High Speed Flow in a Pipe with Cavity

1997 ◽  
Vol 17 (Supplement2) ◽  
pp. 113-116
Author(s):  
Kenji HOSOI ◽  
Masaaki KAWAHASHI ◽  
Hiroyuki HIRAHARA ◽  
Kouju SHIOZAKI ◽  
Kenichirou SATOH
Keyword(s):  
High Speed ◽  
High Speed Flow ◽  
Speed Flow
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