Without rational criteria to determine the Proper Sampled Data Scale （PSDS）, it would result in the expense of the too much unnecessary processing time and storage space in turbulent experiments. A novel approach fo...Without rational criteria to determine the Proper Sampled Data Scale （PSDS）, it would result in the expense of the too much unnecessary processing time and storage space in turbulent experiments. A novel approach for PSDS was established herein on the basis of turbulence theory and statistics. The specific procedure was given by using wavelet tools. A case study to prove the reliability and rationality of this approach was reported, where the sampled hot-wire data were from the experiment of square duct flow and turbulence kinetic energy was selected as the concerned turbulence parameter. It is shown that 2^20 quantities of the sampled data are enough to analyze turbulence kinetic energy in the present experiment. The PSDSs of three turbulence parameters at different Reynolds numbers （Re = 4.60×10^4, 7.68×10^4 and 1.23×10^5） were studied. The results illustrate that the PSDSs increase with the increment of the Reynolds number and the order of concerned turbulence parameter.展开更多
In this paper,the power law of particle size distributions (PSDs) in conventional water treatment processes is developed. After measuring the particle size distributions of raw-water,settled water and filtered water,a...In this paper,the power law of particle size distributions (PSDs) in conventional water treatment processes is developed. After measuring the particle size distributions of raw-water,settled water and filtered water,a mathematical model between particle diameter and the amount of particles was studied. The value of collision frequency factor β in the PSDs model can be used to represent the collision behavior of particles ,and can be used as foundation exponent to choose suitable coagulation to accelerate particles aggregation. At the same time,the relationship between the value of parameter K and the total particles volume V was deduced. K is defined as particle volume exponent,which can represent the total volume of particles. The degression degree of K shows the removal efficiency of potable water treatment units.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.50776056)National High Technology Research and Development of China(863 Program,Grant No.2009AA05Z201)
文摘Without rational criteria to determine the Proper Sampled Data Scale （PSDS）, it would result in the expense of the too much unnecessary processing time and storage space in turbulent experiments. A novel approach for PSDS was established herein on the basis of turbulence theory and statistics. The specific procedure was given by using wavelet tools. A case study to prove the reliability and rationality of this approach was reported, where the sampled hot-wire data were from the experiment of square duct flow and turbulence kinetic energy was selected as the concerned turbulence parameter. It is shown that 2^20 quantities of the sampled data are enough to analyze turbulence kinetic energy in the present experiment. The PSDSs of three turbulence parameters at different Reynolds numbers （Re = 4.60×10^4, 7.68×10^4 and 1.23×10^5） were studied. The results illustrate that the PSDSs increase with the increment of the Reynolds number and the order of concerned turbulence parameter.
基金Sponsored by the National Basic Research Program of China(973)(Grant No.2004CB41850)the Natural Science Foundation of Heilongjiang Prov-ince(Grant No.E200609)
文摘In this paper,the power law of particle size distributions (PSDs) in conventional water treatment processes is developed. After measuring the particle size distributions of raw-water,settled water and filtered water,a mathematical model between particle diameter and the amount of particles was studied. The value of collision frequency factor β in the PSDs model can be used to represent the collision behavior of particles ,and can be used as foundation exponent to choose suitable coagulation to accelerate particles aggregation. At the same time,the relationship between the value of parameter K and the total particles volume V was deduced. K is defined as particle volume exponent,which can represent the total volume of particles. The degression degree of K shows the removal efficiency of potable water treatment units.
