Dynamics of the spout of gas plumes discharging from a melt: Experimental investigation with a large-scale water model
In the present study, the spout region of a gas plume discharging from a melt has been investigated using a water model of 180 cm in height and 160 cm in diameter. The lateral movement of the spout, as measured optically, increases with the gas flow rate and has been found to be ± 20-cm wide or wider, and very fast. The spout height, as measured with video-optical and electrical methods, strongly fluctuates with time. Clear definitions have to be made of the quantities to be determined in the highly dynamic process. Long-time averages of the radial height profiles and momentary maximum height values are reported. It is confirmed that the nondimensional spout height, defined and measured in a certain manner, is independent of the Froude number and of the nondimensional nozzle diameter.
Workflow management techniques were developed in early 1990s,and its critical part was conceptual modeling.As a kind of graphical and mathematical modeling tools,Petri Net is applicable to the modeling requirement of workflow.A method of modeling for workflow based on Generalized Stochastic Petri Net(GSPN) is proposed and the validity and reliability is checked using reachable graph method.By utilizing the equivalence relation between GSPN and Markov chain,a method of combining GSPN and Markov chain is used to analyze the performance of workflow.The effectiveness of this method is verified by an application case,which will help to implement a workflow management system.