MHD Interaction around a Blunt Body in a Hypersonic Unseeded Air Flow: Experimental Results and Numerical Rebuilding

Author(s):  
Andrea Cristofolini ◽  
Carlo Borghi ◽  
Gabriele Neretti ◽  
Francesco Battista ◽  
Antonio Schettino ◽  
...  
1972 ◽  
Vol 38 (311) ◽  
pp. 1753-1762
Author(s):  
Ryuichi MATSUMOTO ◽  
Kyoji KIMOTO ◽  
Nobutaka TSUCHIMOTO

2002 ◽  
Author(s):  
AMALIA R BLACK ◽  
JILL M SUO-ANTTILA ◽  
LOUIS A GRITZO ◽  
PETER J DISIMILE ◽  
JAMES R TUCKER

2009 ◽  
Vol 59 (12) ◽  
pp. 2429-2435 ◽  
Author(s):  
S. J. Han ◽  
C. S. B. Fitzpatrick ◽  
A. Wetherill

Combined rapid gravity filtration and backwash models have been applied to simulate filtration and backwash cycles. The simulated results from the backwash model suggest that an optimum air flow rate exists to maximise particle removal efficiency in the backwash operation for a certain backwash system. The simulation of combined rapid gravity filtration and backwash models suggests that the filter shouldn't be completely cleaned up in the backwash and a certain amount of particles retained on filter grains after backwash can be beneficial for subsequent filtration runs. This is consistent with the experimental results in the literature.


Author(s):  
Yizhong Xu ◽  
Mohamad Y. Mustafa ◽  
Geanette Polanco

Even after many years of the application of numerical CFD techniques to flow through porous fences, still there is disagreement between researchers regarding the best turbulence model to be implemented in this field. Moreover, different sources claim to have achieved good agreement between numerical results and experimental data; however, it is not always possible to compare numerical and experimental results due to the lack of information or variations in test conditions. In this paper, five different turbulence models namely; K-ε models (standard, RNG and Realizable) and K-ω models (Standard and SST), have been applied through a 3D CFD model to investigate air flow behind a porous panel, under the same conditions (boundary conditions and numerical schemes). Results are compared with wind tunnel experiments. Comparison is based on the vertical velocity profile at a location 925 mm downstream of the fence along its center line. All models were capable of reproducing the velocity profile, however, some turbulence models over-predicted the reduction of velocity while it was under-predicted by other models, however, discrepancy between CFD modelling and experimental results was kept around 20%. Comprehensive description of the turbulence structure and the streamlines highlight the fact that the criterion for selecting the best turbulence model cannot rely only on the velocity comparison at one location, it must also include other variables.


Secondary vorticity in the direction of flow is developed after fluid with a non-uniform velocity passes through a bend. The secondary flow may be increased or decreased by reversal of the radius of curvature of the bend, depending on the location of the reversal. The general behaviour of the secondary flow in a bend in which the radius of curvature is repeatedly reversed is analyzed by assuming the centre line of the bend is a sine curve. The resulting differential equation describing the flow is non-linear, and a variety of solutions are obtained for different entry conditions. These solutions are compared with experimental results obtained from observations of the air flow through various configurations of pipe.


2015 ◽  
Vol 1130 ◽  
pp. 400-405 ◽  
Author(s):  
Ming Qing Huang ◽  
Yi Ming Wang ◽  
Sheng Hua Yin ◽  
Ai Xiang Wu

To assess the effects of forced aeration on leaching dynamics of sulfides, five sets of column bioleaching of copper sulfides using Acidithiobacillus ferrooxidans were conducted when the aeration rates ranged from 0 to 150 L/h. The experimental results show that forced aeration can ameliorate the porosity and flow rates throughout the heap, and improve the bacterial concentration and oxidative ability. Forced aeration at the column bottom can enhance the interactions of air, flow and particles, and then facilitate the heap porosity and connectivity. The oxidant Fe3+ concentrations are proportional to the aeration rates, and lead to an accelerating dissolution rate of sulfides. In addition, the bacterial concentration, oxidative ability and Fe3+ concentration are susceptible to aeration rates, and the forced aeration remarkably enhances the bioleaching when aeration rates are higher than 60 L/h compare to those with none or slight aeration.


Author(s):  
Uroš Kalabić ◽  
Ilya Kolmanovsky ◽  
Julia Buckland

This paper presents a formulation and an application of a high-gain multi-input observer to estimate the compressor flow in turbocharged gasoline engines. Such an observer is desired in vehicles lacking a mass air flow sensor yet in which compressor flow needs to be known; for instance, it is desired in order to apply a reference governor for surge constraint avoidance. In this application, a fast estimate of the compressor flow is required so that the reference governor can take action before the compressor goes into surge. The multi-input observer uses pressure measurements and cylinder flow to estimate the compressor flow. This paper presents the derivation of the observer and both simulation and experimental results showing its feasibility in estimating the compressor flow.


1976 ◽  
Vol 1 (15) ◽  
pp. 170
Author(s):  
Nabil Ismail

Based on a literature review of theoretical and experimental work on air-bubble systems, guidelines for the ideal design of submerged distributors discharging air into water are presented. A comprehensive study of gas-liquid dispersions was carried out to find out the effect of physical properties, distributor arrangement, and the air flow rate, on the flow pattern within the jet. This review revealed that the distributor arrangement largely influences the characteristics of the dispersion within the zone of flow establishment. Also, upon analyzing the experimental results of air-water systems, it was found that the zone of flow establishment extends to greater distances of the water depth than that in the case of one-phase turbulent plumes. Furthermore, the experimental results showed that the efficiency of air bubble plumes can be increased by the proper design of the distributor. Recommendations for the distributor design are given, which include, diameter of orifices and their spacings, pressure drop across orifices, number of manifolds, and the maximum air flow rate.


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