This paper presents a study on the numerical simulation of planing crafts sailing in regular waves. This allows an accurate estimate of the seas keeping performance of the high speed craft. The simulation set in six-d...This paper presents a study on the numerical simulation of planing crafts sailing in regular waves. This allows an accurate estimate of the seas keeping performance of the high speed craft. The simulation set in six-degree of freedom motions is based on the Reynolds averaged Navier Stokes equations volume of fluid （RANSE VOF） solver. The trimming mesh technique and integral dynamic mesh method are used to guarantee the good accuracy of the hydrodynamic force and high efficiency of the numerical simulation. Incident head waves, oblique waves and beam waves are generated in the simulation with three different velocities （Fn =1.0, 1.5, 2.0）. The motions and sea keeping performance of the planing craft with waves coming from different directions are indicated in the flow solver. The ship designer placed an emphasis on the effects of waves on sailing amplitude and pressure distribution of planing craft in the configuration of building high speed crafts.展开更多
A new seabed sediment fidelity sampler was developed and its thermal insulation performance was studied and analyzed. The temperature distribution simulation indicated that the sample quality could be insured by using...A new seabed sediment fidelity sampler was developed and its thermal insulation performance was studied and analyzed. The temperature distribution simulation indicated that the sample quality could be insured by using this new sampler. Based on ANSYS10, the temperature finite element model of the sample cylinder was established. According to the law of conservation of energy, the unsteady heat transmit equation of the sampler under solid-liquid coupling condition was derived, then the mathematical model calculation was carried out by using a mixed finite-element finite-difference method, and two thermal insulation methods were used. The simulation was carried out by using the thickness of the thermal insulation layer and heat conductivity as the variable parameters and the temperature distribution of the sampler and related influencing factors were obtained. Optimization analysis was conducted using the simulation data and related parameters and the magnitude ranges of the parameters were obtained that could meet the design temperature requirements. The experimental data and simulation results indicated that the results were in good agreement with the realities, and this sampler might be of value for seabed sediment sampler design and manufacture.展开更多
A FCC mechanism model was used to predict the effects of propylene promoter in a 3.0 Mt/a FCCU. The FCC mechanism model was developed based on one set of commercial FCC data without using the promoter, and was modifie...A FCC mechanism model was used to predict the effects of propylene promoter in a 3.0 Mt/a FCCU. The FCC mechanism model was developed based on one set of commercial FCC data without using the promoter, and was modified by using another set of commercial FCC data with 3m% promoter in the catalyst inventory, and the calculations by means of this simulation model were performed to predict the data of the FCC unit containing 4m% promoter in the catalyst inventory. The test results showed that the calculated values agreed well with the data obtained from the commercial FCC unit, in which the deviations of calculated product yields versus the actual product yields at the commercial FCC unit were equal to 1.74 percentage points for gasoline, 2.59 percentage points for diesel, 1.50 percentage points for dry gas and LPG, and 0.28 percentage points for coke. The proposed method regarding the development of a simulation model and modifications to the model for commercial FCC unit was feasible.展开更多
基金Foundation item： Supported by the National Natural Science Foundation of China under Grant No. 551009038 and the specialized research fund for the doctoral program of higher education under Grant No. 200802170010
文摘This paper presents a study on the numerical simulation of planing crafts sailing in regular waves. This allows an accurate estimate of the seas keeping performance of the high speed craft. The simulation set in six-degree of freedom motions is based on the Reynolds averaged Navier Stokes equations volume of fluid （RANSE VOF） solver. The trimming mesh technique and integral dynamic mesh method are used to guarantee the good accuracy of the hydrodynamic force and high efficiency of the numerical simulation. Incident head waves, oblique waves and beam waves are generated in the simulation with three different velocities （Fn =1.0, 1.5, 2.0）. The motions and sea keeping performance of the planing craft with waves coming from different directions are indicated in the flow solver. The ship designer placed an emphasis on the effects of waves on sailing amplitude and pressure distribution of planing craft in the configuration of building high speed crafts.
基金supported by The Key Technologies Research and Development Program of Shandong Province (Grant No.2006GG2206013)Foundation Sciences Funds of Qingdao (2007-2-3-15-jch)State Key Laboratory of Ocean Engineering at Shanghai Jiao Tong University (Grant No. XXXX0701)
文摘A new seabed sediment fidelity sampler was developed and its thermal insulation performance was studied and analyzed. The temperature distribution simulation indicated that the sample quality could be insured by using this new sampler. Based on ANSYS10, the temperature finite element model of the sample cylinder was established. According to the law of conservation of energy, the unsteady heat transmit equation of the sampler under solid-liquid coupling condition was derived, then the mathematical model calculation was carried out by using a mixed finite-element finite-difference method, and two thermal insulation methods were used. The simulation was carried out by using the thickness of the thermal insulation layer and heat conductivity as the variable parameters and the temperature distribution of the sampler and related influencing factors were obtained. Optimization analysis was conducted using the simulation data and related parameters and the magnitude ranges of the parameters were obtained that could meet the design temperature requirements. The experimental data and simulation results indicated that the results were in good agreement with the realities, and this sampler might be of value for seabed sediment sampler design and manufacture.
文摘A FCC mechanism model was used to predict the effects of propylene promoter in a 3.0 Mt/a FCCU. The FCC mechanism model was developed based on one set of commercial FCC data without using the promoter, and was modified by using another set of commercial FCC data with 3m% promoter in the catalyst inventory, and the calculations by means of this simulation model were performed to predict the data of the FCC unit containing 4m% promoter in the catalyst inventory. The test results showed that the calculated values agreed well with the data obtained from the commercial FCC unit, in which the deviations of calculated product yields versus the actual product yields at the commercial FCC unit were equal to 1.74 percentage points for gasoline, 2.59 percentage points for diesel, 1.50 percentage points for dry gas and LPG, and 0.28 percentage points for coke. The proposed method regarding the development of a simulation model and modifications to the model for commercial FCC unit was feasible.
