Three-dimensional Density Measurement and Reconstruction of Asymmetric Flow Field by Colored Grid Background Oriented Schlieren (CGBOS) Technique

2011 ◽  
Author(s):  
Masanori Ota ◽  
Kenta Hamada ◽  
Hiroko Kato ◽  
Ryuki Sakamoto ◽  
Kazuo Maeno
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Density Measurement ◽  
Asymmetric Flow ◽  
Background Oriented Schlieren

scholarly journals Numerical simulation of 3-D flow around sounding rocket in the lower thermosphere

2006 ◽  
Vol 24 (1) ◽  
pp. 89-95 ◽  
Author(s):  
J. Kurihara ◽  
K.-I. Oyama ◽  
N. Iwagami ◽  
T. Takahashi
Keyword(s):  
Lower Thermosphere ◽  
Three Dimensional ◽  
Density Measurement ◽  
Direct Simulation Monte Carlo ◽  
Sounding Rocket ◽  
Atmospheric Conditions ◽  
Axially Symmetric ◽  
Asymmetric Flow ◽  
Dsmc Method ◽  
Spin Modulation

Abstract. Numerical simulations using the Direct Simulation Monte Carlo (DSMC) method are known to be useful for analyses of aerodynamic effects on in-situ rocket measurements in the lower thermosphere, but the DSMC analysis of a spin modulation caused by an asymmetric flow around the rocket spin axis has been restricted to the two-dimensional and axially symmetric simulations in actual sounding rocket experiments. This study provides a quantitative analysis of the spin modulation using a three-dimensional (3-D) simulation of the asymmetric flow with the DSMC method. Clear spin modulations in the lower thermospheric N2 density measurement by a rocket-borne instrument are simulated using the rocket attitude and velocity, the simplified payload structure, and the approximated atmospheric conditions. Comparison between the observed and simulated spin modulations show a very good agreement within 5% at around 100km. The results of the simulation are used to correct the spin modulations and derive the absolute densities in the background atmosphere.

Quantitative Measurement of Temperature Gradient in Natural Heat Convection Using Color-Stripe Background Oriented Schlieren (CSBOS) Technique and Computed Tomography (CT) Method

2011 ◽  
Author(s):  
Muhammad Falak Zeb ◽  
Masanori Ota ◽  
Kazuo Maeno
Keyword(s):  
Temperature Gradient ◽  
Flow Field ◽  
Quantitative Measurement ◽  
Three Dimensional ◽  
Image Data ◽  
Flow Fields ◽  
Two Dimensions ◽  
Ct Reconstruction ◽  
Optimum Energy ◽  
Background Oriented Schlieren

Quantitative image analysis and measurement of flow fields in convective heat transfer has great importance for the optimum energy consumption problems. In natural and forced convection phenomena of fluids, the complexity of flow field prevents us from detailed three dimensional (3D) experimental analyses of steady/unsteady dynamics in fluids. These flow fields have locally different density and temperature values and yet to be observed quantitatively. Recent development of the Particle Image Velocimetry (PIV) and Particle Tracking Velocimetry (PTV) techniques lead us to the quantitative investigation of flow fields in experimental researches. On the other hand, in image measurements density and temperature distributions have been grasped only in two-dimensions (2D). These qualitative image analyses of flow fields were obtained by using classical flow visualizing techniques, such as shadowgraph and color schlieren method. This paper describes the quantitative measurement of convective flow field using our originally proposed color striped background oriented schlieren (CSBOS) method. The obtained measured image data is used for CT reconstruction and 3D temperature gradient distributions.

THE INTERNAL FLOW FIELD ASSOCIATED WITH YAWED THREE-DIMENSIONAL RECTANGULAR CAVITIES

2000 ◽  
Vol 7 (3) ◽  
pp. 14
Author(s):  
Eric Savory ◽  
Norman Toy ◽  
Shiki Okamoto ◽  
Yoko Yamanishi
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Internal Flow
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