Drilling operations in polar regions and mountainous areas are complicated by nature of the extreme environment. Yet conventional rotary drilling technologies can be used to drill ice for scientific samples and oth- e...Drilling operations in polar regions and mountainous areas are complicated by nature of the extreme environment. Yet conventional rotary drilling technologies can be used to drill ice for scientific samples and oth- er research. Due to such reasons as power consumption and weight complications, it is hard to apply a conven- tional rotary drilling rig for glacial exploration. Use of small, relatively lightweight, portable engine-powered drilling systems in which the drill lifting from the borehole is carried by the winch. It is reasonable enough for near-surface shallow ice-drilling down to 50 m. Such systems can be used for near-surface ablation-stakes in- stallation, also temperature measurements at the bottom of active strata layer, revealing of anthropogenie pollu- tion, etc. The specified used in this research is an auger ice drill powered by a gasoline engine. At this stage, it is crucial to choose effective drilling parameters such as weight on bit （WOB） and drill bit rotation rate. Sen- sors equipped on the rig have measured the main parameters of the drilling process, such as drill speed, WOB, drill rotation speed, torque and temperature. This paper addresses research on drilling parameters of engine powered auger ice drill and supplies some recommendations for optimization of any ice-core drilling process.展开更多
In this paper, the distributions of particle velocity in a gas–solid fluidized bed with branched pipe distributor or circle distributor were measured by using a laser Doppler velocimetry. Our results show that, withi...In this paper, the distributions of particle velocity in a gas–solid fluidized bed with branched pipe distributor or circle distributor were measured by using a laser Doppler velocimetry. Our results show that, within a certain range of superficial gas velocity, when using circle distributor, the particle velocity is large and the distribution of the particle velocity is even more compared with the branched pipe distributor. On the basis of the amplitude of tangential movement statistics, the amplitude of tangential movement statistics(AVATMS) decreases with increasing the axial height under the appropriate superficial gas velocity.展开更多
In recent years, tighter regulation has been already enforced on harmful substances such as NOx, CO, and particles. Considering the above situation, it is important to monitor controlling factors of engine systems in ...In recent years, tighter regulation has been already enforced on harmful substances such as NOx, CO, and particles. Considering the above situation, it is important to monitor controlling factors of engine systems in order to improve efficiencies of their operations. As to car engines, an increasing concern in environmental issues such as air pollution, global warming and petroleum depletion has helped drive researches into various ways. Laser diagnostics has been applied to measure species concentration in the actual industrial fields. However there are several challenges to proceed in applying laser diagnostics to practical application. Especially stability of the measurement system is one of the most difficult issues. The purpose of this research is the development of a prompt measurement technique which can be applicable to various engine conditions. The Tunable Diode Laser Absorption Spectroscopy （TDLAS） using the hollow fiber has been developed to satisfy above requirements. By using a hollow fiber, misalignment of an optical axis and vulnerability of measurement environment such as vibration can be greatly reduced with sensitive and fast response features. It was demonstrated that this method can be applicable to measure gas compositions in engine exhaust with a range of millisecond response time. A sensitive method using tunable UV diode laser absorption spectroscopy was also discussed to detect NOx in exhausts.展开更多
July 25, 2014 / Accepted： August 18, 2014 / Published： November 25, 2014 Abstract： This paper presents the measurement results of a l1/2 stage LPT （low pressure turbine） test rig at Graz University of Technology ...July 25, 2014 / Accepted： August 18, 2014 / Published： November 25, 2014 Abstract： This paper presents the measurement results of a l1/2 stage LPT （low pressure turbine） test rig at Graz University of Technology incorporating two different rotor geometries： one with a regular blade loading and the other with a highly loaded blade geometry. The test rig was designed in cooperation with MTU Aero Engines and represented the last 1.5 stages of a commercial aero engine. Considerable efforts were put on the adjustment of all relevant model parameters （Mach number, blade count ratio, airfoil aspect ratio, blade loading, etc.） to reproduce the full scale LPT situation. The rig diameter is approximately half of that of a commercial aero engine LPT. The number of blades and vanes for the two investigated stages as well as the pressure ratio and power output are identical, resulting in a decrease in rotational speed of the HSL （high stage loading） rotor. Measurement data from a FRAPP （fast response pressure probe） is used to compare the flow fields of the two different stages. The effect of the different stage designs can be seen when comparing the exit flow fields. The highly loaded stage shows a more pronounced tip leakage vortex compared to the datum stage. The highly loaded stage shows wider wakes with a lower total pressure deficit. The fluctuations of total pressure within the flow field are directly related to the upstream wake. If the measurement position is located within a stator wake, the fluctuations are significantly smaller than that out of the wake.展开更多
基金Supported by projects of National Science Foundation of China(No.41327804)the Geological Survey of China(No.3R212W324424)
文摘Drilling operations in polar regions and mountainous areas are complicated by nature of the extreme environment. Yet conventional rotary drilling technologies can be used to drill ice for scientific samples and oth- er research. Due to such reasons as power consumption and weight complications, it is hard to apply a conven- tional rotary drilling rig for glacial exploration. Use of small, relatively lightweight, portable engine-powered drilling systems in which the drill lifting from the borehole is carried by the winch. It is reasonable enough for near-surface shallow ice-drilling down to 50 m. Such systems can be used for near-surface ablation-stakes in- stallation, also temperature measurements at the bottom of active strata layer, revealing of anthropogenie pollu- tion, etc. The specified used in this research is an auger ice drill powered by a gasoline engine. At this stage, it is crucial to choose effective drilling parameters such as weight on bit （WOB） and drill bit rotation rate. Sen- sors equipped on the rig have measured the main parameters of the drilling process, such as drill speed, WOB, drill rotation speed, torque and temperature. This paper addresses research on drilling parameters of engine powered auger ice drill and supplies some recommendations for optimization of any ice-core drilling process.
基金Supported by the National High-Tech R&D Program of China(2011AA05A204)the Fundamental Research Funds for the Central Universities(222201717013)
文摘In this paper, the distributions of particle velocity in a gas–solid fluidized bed with branched pipe distributor or circle distributor were measured by using a laser Doppler velocimetry. Our results show that, within a certain range of superficial gas velocity, when using circle distributor, the particle velocity is large and the distribution of the particle velocity is even more compared with the branched pipe distributor. On the basis of the amplitude of tangential movement statistics, the amplitude of tangential movement statistics(AVATMS) decreases with increasing the axial height under the appropriate superficial gas velocity.
文摘In recent years, tighter regulation has been already enforced on harmful substances such as NOx, CO, and particles. Considering the above situation, it is important to monitor controlling factors of engine systems in order to improve efficiencies of their operations. As to car engines, an increasing concern in environmental issues such as air pollution, global warming and petroleum depletion has helped drive researches into various ways. Laser diagnostics has been applied to measure species concentration in the actual industrial fields. However there are several challenges to proceed in applying laser diagnostics to practical application. Especially stability of the measurement system is one of the most difficult issues. The purpose of this research is the development of a prompt measurement technique which can be applicable to various engine conditions. The Tunable Diode Laser Absorption Spectroscopy （TDLAS） using the hollow fiber has been developed to satisfy above requirements. By using a hollow fiber, misalignment of an optical axis and vulnerability of measurement environment such as vibration can be greatly reduced with sensitive and fast response features. It was demonstrated that this method can be applicable to measure gas compositions in engine exhaust with a range of millisecond response time. A sensitive method using tunable UV diode laser absorption spectroscopy was also discussed to detect NOx in exhausts.
文摘July 25, 2014 / Accepted： August 18, 2014 / Published： November 25, 2014 Abstract： This paper presents the measurement results of a l1/2 stage LPT （low pressure turbine） test rig at Graz University of Technology incorporating two different rotor geometries： one with a regular blade loading and the other with a highly loaded blade geometry. The test rig was designed in cooperation with MTU Aero Engines and represented the last 1.5 stages of a commercial aero engine. Considerable efforts were put on the adjustment of all relevant model parameters （Mach number, blade count ratio, airfoil aspect ratio, blade loading, etc.） to reproduce the full scale LPT situation. The rig diameter is approximately half of that of a commercial aero engine LPT. The number of blades and vanes for the two investigated stages as well as the pressure ratio and power output are identical, resulting in a decrease in rotational speed of the HSL （high stage loading） rotor. Measurement data from a FRAPP （fast response pressure probe） is used to compare the flow fields of the two different stages. The effect of the different stage designs can be seen when comparing the exit flow fields. The highly loaded stage shows a more pronounced tip leakage vortex compared to the datum stage. The highly loaded stage shows wider wakes with a lower total pressure deficit. The fluctuations of total pressure within the flow field are directly related to the upstream wake. If the measurement position is located within a stator wake, the fluctuations are significantly smaller than that out of the wake.
