An experimental study has been performed to investigate pool water instantaneous flash evaporation in a rectangle chamber. Some key parameters such as superheat, initial water temperature and water level have been stu...
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An experimental study has been performed to investigate pool water instantaneous flash evaporation in a rectangle chamber. Some key parameters such as superheat, initial water temperature and water level have been studied. The water level was at 40 mm, 60 mm, 100 mm, 150 mm. Initial conditions of the liquid varied from 36C to 88C temperature and 2.1C to 48C superheat. The experimental results showed that the initial water temperature, the superheat and the water level are the key parameters. The experimental results showed that the greater the superheat and the higher the initial water level approaches, the longer the flashing will persist. Under a constant superheat, the initial water temperature has little influence on duration of flashing. Experimental study allows us to correlate the flashing duration time with the superheat and the initial water level as well as the initial water temperature.
Based on the wavelet analysis theory of signal singularity detection, the critical heat flux (CHF) and minimum film boiling starting point (qmin) of boiling curves can be detected and analyzed by using the wavelet mul...
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Based on the wavelet analysis theory of signal singularity detection, the critical heat flux (CHF) and minimum film boiling starting point (qmin) of boiling curves can be detected and analyzed by using the wavelet multi-resolution analysis. To predict the CHF in engineering, empirical relations were obtained based on genetic algorithm. The results of wavelet detection and genetic algorithm prediction are consistent with experimental data very well.
The explosion limits of dimethyl ether, methane and different mixtures of dimethyl ether and methane were measured under the temperature ranging from room temperature to 80C and the pressure ranging from 0.1 to 0.3 MP...
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The explosion limits of dimethyl ether, methane and different mixtures of dimethyl ether and methane were measured under the temperature ranging from room temperature to 80C and the pressure ranging from 0.1 to 0.3 MPa. In addition, the effects of temperature and pressure on the explosion limit were analyzed, and the accuracies of some theoretical calculation models of explosion limit were tested with the experimental results.
An algorithm for bubble packing method based unstructured grid generation of a curved-edge polygon is developed to avoid bubble departure from a curved boundary during dynamic bubble movement. The curve boundary is ma...
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An algorithm for bubble packing method based unstructured grid generation of a curved-edge polygon is developed to avoid bubble departure from a curved boundary during dynamic bubble movement. The curve boundary is mapped into a straight line to allow bubble adding and moving. Then the bubble position is mapped into the curve boundary by the arc-length parameterization method. Combined with conventional methods, a new method to judge a point in a given curved-edge polygon is proposed. Local grid refinement is realized by adding different size bubbles to the real and artificial vertices and setting the bubble's radius by the weighted average method. Moreover, the SIMPLE algorithm on unstructured collocated grid systems is developed and applied to simulate the lid-driven flow in a polar cavity. The numerical simulation results agree well with the experimental data under different Reynolds numbers.
In present paper, the effect of velocity ratio on plane mixing layer is experimentally investigated with Particle Image Velocimetry (PIV). The velocity ratio between low- and high-speed side are 0.25, 0.33 and 0.50, r...
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In present paper, the effect of velocity ratio on plane mixing layer is experimentally investigated with Particle Image Velocimetry (PIV). The velocity ratio between low- and high-speed side are 0.25, 0.33 and 0.50, respectively. The Reynolds number based on the velocity difference of two streams and hydraulic diameter of the channel ranges from 15840~132000. The results indicate that the maximum mean Reynolds stress on the same cross section increases with Reynolds number increasing but decreases with velocity ratio increasing at the equal Reynolds number. The mean vorticity increases with Reynolds number increasing on the same cross-section and increases with the velocity ratio increasing at the equal Reynolds number. The maximum non-dimensional mean vorticity decreases according to an exponential law along the stream-wise direction, and the decreasing speed of maximum mean vorticity increases with the velocity ratio increasing.
Low-pressure premixed laminar flames of 1,3-butadiene/oxygen /argon and 1,3-butadiene+acetylene/oxygen/argon have been investigated with tunable synchrotron photoionization and molecular beam mass spectrometry. Flame ...
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Low-pressure (4.0 kPa) premixed laminar 2,5-dimethylfuran (DMF)/oxygen/argon flame with an equivalence ratio (ø) of 2.0 was studied with tunable vacuum ultraviolet synchrotron radiation photoionization and molecu...
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Low pressure premixed laminar n-heptane/propane/O2/N2 flames were investigated with tunable synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam sampling mass spectrometry. Three flames with differe...
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Large fraction of the low-pressure turbine cascade boundary layer is laminar flow due to low Reynolds number. High-lift low-pressure turbine blade leads to increase the adverse pressure gradient at rear of the turbine...
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