In order to study features of rock–water interaction, a self-developed experimental system called Intelligent Testing System for Water Absorption in Deep Soft Rocks(ITSWADSR) was utilized to analyze the hydrophilic b...In order to study features of rock–water interaction, a self-developed experimental system called Intelligent Testing System for Water Absorption in Deep Soft Rocks(ITSWADSR) was utilized to analyze the hydrophilic behaviors of natural soft rock at high stress state. Combining X-ray diffraction and mercury injection test, main influencing factors on hydrophilic characteristics were studied. According to the results, it could be concluded as the following:(1) the effective porosity, and the content of illite, illite/smectite formation(S = 5%) and kaolinite have positive correlation with the water absorption capacity of rock; meanwhile, the initial moisture content, fractal dimension of effective pores, illite/smectite formation(S = 30%) and chlorite present negative correlation;(2) among the positive factors, the ascending order is kaolinite, illite/smectite formation(S = 5%) and illite;(3) the descending order among the negative factors are chlorite, illite/smectite formation(S = 30%) and fractal dimension of the effective pores;(4) influence of effective porosity on the pressurized water absorbing capacity of rock is minimal, while it is maximal in the process of no pressurized water absorption.展开更多
Research on the Asian-Pacific monsoon has a long history. This paper starts by summarizing field experiments investigating the Asian-Pacific monsoon. Since the 1960s, a number of international and regional monsoon pro...Research on the Asian-Pacific monsoon has a long history. This paper starts by summarizing field experiments investigating the Asian-Pacific monsoon. Since the 1960s, a number of international and regional monsoon projects and field experiments have been carried out, and substantial progress regarding research on the Asian-Pacific monsoon has been made. Second, the onset and the seasonal march of the Asian summer monsoon and the annual cycle of active and break periods of the monsoon, which are characterized by precipitation maxima and minima, are studied. Since the inter-tropical convergence zone (ITCZ or TCZ) is the dominating weather system and is the major birthplace of typhoons and tropical convective systems, the monsoonal rainfall and ITCZ are analyzed after the onset of the Asian mon- soon. Finally, because the ITCZ has a close relationship with tropical convective systems and rainfall events in monsoon regions, analyses of the developments of deep convection and rainfall events are briefly introduced.展开更多
The pull-out capacities for soil nailing systems comprising of one single 29 mm diameter(type A) and four 16 mm diameter(type B) rebars with grouted cement were examined.A field test and numerical analysis for the typ...The pull-out capacities for soil nailing systems comprising of one single 29 mm diameter(type A) and four 16 mm diameter(type B) rebars with grouted cement were examined.A field test and numerical analysis for the type A and type B systems were carried out to investigate the pull-out capacities and the slope stability reinforcement efficiency in soil and rock slopes.The results of the pull-out tests show the mobilized shear force and load transfer characteristics with respect to soil depth.The load-displacement relationship was examined for both type A and type B systems.Slope stability analyses were carried out to study the relationships between soil and nail reinforcement and bending stiffness as well as combined axial tension and shear forces.Factors of safety were calculated in relation to the number of nails and their outside diameters.Both soil and rock slopes were included in this evaluation.展开更多
Sodium hypochlorite and ozone are the principal active substances and usually employed in ballast water management systems. In the present study, the authors focus on the effect of these active substances to the maaix...Sodium hypochlorite and ozone are the principal active substances and usually employed in ballast water management systems. In the present study, the authors focus on the effect of these active substances to the maaix polymer of coating. In order to obtain such information, the authors investigated the penetration of active substances to the polymer from cross section of specimens introduced by SAICAS (surface and interracial cutting analysis system), followed by FT-IR-ATR (Fourier transform infrared and attenuated total reflectance) spectroscopy analysis from Z direction of cross section. The corrosion test of coating panels by these active substances (control as artificial seawater) has been conducted for 120 days. The results show that the depth profile of each active substance is around few dozens of micrometers from coating surface. The criteria of corrosion test cannot be determined by these results due to lacking in actual corrosion data immersed for 15 years under active substances. However, the authors evaluated the effect on ballast tank coating systems by active substances using analytical methods of SAICAS and FT-IR-ATR spectroscopy.展开更多
A series of water absorption tests on dried soft rock have been conducted by the intelligent testing system for water absorption tests in deep soft rock, including tests of water absorption with and without pres- sure...A series of water absorption tests on dried soft rock have been conducted by the intelligent testing system for water absorption tests in deep soft rock, including tests of water absorption with and without pres- sure. The results show that the water absorbing capacity of rock with a certain pressure is larger than that of rock without pressure: however, the relationship between the water absorbing percentage and the time can be expressed by w(t) = a(l - e^-bt). In hi-logarithmic coordinates, the hydrophilic relationship with time in tests with pressure could be characterized by linearity, while they present concave or convex in tests without pressure. Based on the hypothesis that each influential factor is irrelevant and they have a linear correlation with the water absorbing capacity, we calculated the weight coefficient of each factor according to experimental results under different conditions. The calculations demonstrate that the effec- tive porosity, content of smectite and kaolinite are all positively correlated with the water absorption capacity of rock; meanwhile, the fractal dimension of the effective pores presents a negative correlation with the water absorption capacity of rock. The water absorption capacity with pressure increases with increasing illite, chlorite and chlorite/smectite formation and a decrease in illite/smectite formation and the fractal dimension of the effective pores, while it is opposite in tests without pressure. The weight coefficient of smectite is smallest among positive factors, and the fractal dimension of the effective pores is the smallest amongst the negative factors.展开更多
The research goal is to develop a new solar water heater system(SWHS) that uses a solar bubble pump instead of an electric pump.The pump is powered by the steam produced from an evacuated tube collector.Therefore,heat...The research goal is to develop a new solar water heater system(SWHS) that uses a solar bubble pump instead of an electric pump.The pump is powered by the steam produced from an evacuated tube collector.Therefore,heat could be transferred downward from the collector to a hot water storage tank.The designed system consists of two sets of heat-pipe evacuated tube collectors,a solar bubble pump installed at an upper level and a water storage tank with a heat exchanger at a lower level.Discharge heads of 1 and 5 m were tested.The bubble pump could operate at the collector temperature of about 90-100 ℃ and vapor gage pressure of 80-90 kPa.It is found that water circulation within the SWHS depends on the incident solar intensity and system discharge head.Experimental investigations are conducted to obtain the system thermal efficiencies from the hourly,daily and long-term performance tests.The thermal performance of the proposed system is compared with conventional solar water heaters.The results show that the proposed system achieves system characteristic efficiency of 10% higher than that of the conventional systems using electric pump if taking the consumption of electric power into account.And the former is a zero carbon system.展开更多
Bali Tourism Development Corporation's lagoon (BTDC lagoon) has been used for treating wastewaters that come from all facilities available in the Nusa Dua Resort tourist area. Reuse of the lagoon effluent is limite...Bali Tourism Development Corporation's lagoon (BTDC lagoon) has been used for treating wastewaters that come from all facilities available in the Nusa Dua Resort tourist area. Reuse of the lagoon effluent is limited for some applications due to salt and suspended solid contents. Application of an integrated membrane system for improving the water quality of the lagoon effluent which is suitable for various uses is under consideration. In this work an ultraflltration (UF) pilot performance for possible pretreatment of Reverse Osmosis (RO) was investigated. The results showed that permeate quality was stable (less than 0.5 NTU), regardless of concentrating and diluting retentate in each cycle and fouling for a long duration of operation. However, the water quality obtained with this membrane was not enough to be directly used. The permeate quality obtained from the UF system fulfils the requirement for the optimal operation of reverse osmosis. Moreover, appropriate intermittent-backwash operation was fairly effective to maintain the fluxes at a reasonable level.展开更多
In response to the high requirements of industrial precision test, presenting a method of testing relative relation of space points was studied. The spatial-coordinate testing system was established by using high prec...In response to the high requirements of industrial precision test, presenting a method of testing relative relation of space points was studied. The spatial-coordinate testing system was established by using high precision theodolites and horizontal staff. The related test was conducted with the use of the space intersection and the precision was evaluated based on the error of baseline. In the practical application of radar-development base, the relative relation of space points was implemented by using electronic theodolite and horizontal staff, which can be easily operated. Furthermore, it can be conveniently used to test small areas where the instruments are difficult to be installed and for high industrial requirements of precision test. The test results can fully meet the strict industrial requirements.展开更多
The effluents of textile dyes are highly colored, and disposal of the wastes into receiving waters cause damage to the environment, therefore dyes removal is of great importance. In this research, removal of Orange II...The effluents of textile dyes are highly colored, and disposal of the wastes into receiving waters cause damage to the environment, therefore dyes removal is of great importance. In this research, removal of Orange II, Remazol Blue, Methyl red, Malachite green and Safranin dyes by Pseudomonas fluorescens was studied in batch system as function of temperature, pH and initial dye concentration. The rate of removal dyes was studied by using pectrophotometer. The optimum value was determined as pH 7 for all dyes tested about 87.8-72.7%, and optimum temperature for removal of all tested dyes was 30℃ about 86.6-60.8%. Higher removal of dyes observed at 25 mL for all tested dyes about 91.9-72,7%. In general, the increase in dye concentration inhibited the growth of bacteria. Pseudomonasfluorescens showed higher removal of Orange II among the dyes tested.展开更多
This study sought to assess Gweru's water supply system from the source to the consumer to find out whether the water is safe for domestic purposes, mainly consumption. Water samples were taken from Gwenoro dam (raw...This study sought to assess Gweru's water supply system from the source to the consumer to find out whether the water is safe for domestic purposes, mainly consumption. Water samples were taken from Gwenoro dam (raw water), Gwenoro treatment plant (treated water) as well as from GIS-generated random points of residential areas closest to Gwenoro and furthest from both the dam and the treatment plant. These were taken for laboratory testing where parameters like pH, hardness, turbidity and DO (dissolved oxygen) were tested. Questionnaires were used to solicit the views of the consumers on water quality and water service delivery from eight randomly selected residential suburbs. Interviews were also administered to Gwenoro Water Treatment Plant superintendent and deputy to get insight into the day to day challenges that they have to grapple with. Results generally show that treated water from Gwenoro treatment plant is relatively safe to drink for those who have access to it. However, some consumer points like Mkoba 13 and Mkoba 18 receive water whose DO is out of the recommended range. Suburbs which lie on higher ground like Mkoba 19 and Mkoba 14 however rarely receive water from Gwenoro with some residents of Mkoba 19 having had no water from their taps for more than three years now. The study recommends that new equipment be bought for the treatment plant so that treated water reaches all parts of the city. Newly resettled farmers in the Upper Runde Catchment must be resettled elsewhere while urban stream bank cultivation must be banned to reduce water pollution as well as possible sedimentation of Gwenoro dam.展开更多
The performance of a BTES (borehole thermal energy storage) system is primarily governed by ground heat flux, soil thermal properties and groundwater conditions. However, the design of the heat exchanger used within...The performance of a BTES (borehole thermal energy storage) system is primarily governed by ground heat flux, soil thermal properties and groundwater conditions. However, the design of the heat exchanger used within the BTES system can also make a significant difference in the efficiency of the system. A thermal response test was carded out for a Kelix GHE (ground heat exchanger) system, the latest innovation in geothermal ground loop construction, on an Ecofarm in the town of Caledon East, Ontario, Canada. In addition, a verifying test was performed for a CEES (conventional earth energy system) located 6 m away from the Kelix GHE. The boreholes for these two different heat exchanger designs were drilled with the same diameter, to the same depth and were located in the same/identical geo-hydrological conditions. The response test provided the effective average of undisturbed ground temperature, geothermal properties including thermal conductivity, heat capacity and thermal resistance between the fluid and the borehole wall. The mathematical analysis method used for the response test is presented here. Results of the response test were verified, analyzed and are further discussed.展开更多
This research presents the results of system validation tests for an SOFC power system. In the study, the system was heated up without electric device, i.e., the fuel providing the required thermal energy through an i...This research presents the results of system validation tests for an SOFC power system. In the study, the system was heated up without electric device, i.e., the fuel providing the required thermal energy through an integrated BOP (balance of plant). The ex-situ experiments, without an SOFC stack installed in the system, were fast conducted to investigate the operability of a BOP apparatus. It was found that the BOP possessed high conversion rates for both steam reforming and water gas shift reactions. The total fuel concentration of hydrogen and carbon monoxide from the reformer was around 91.2%. The system validation tests showed that, with the natural gas as fuel, the output power from the stack reached to 1,060 W, while the fuel utilization efficiency and electrical efficiency were 67.16% and 45.0%, respectively. A steady 600-hour system operation test was carried out at an average system temperature of 694℃. Of which, a 36-cell stack was employed for the test. Meanwhile, the current, voltage and output power were 26 A, 32.3 V and 840 W, respectively, and its electrical efficiency was around 33.4%.展开更多
A performance study of a water ramjet engine is described.The engine is powered by the reaction of a magnesium-based propellant and ingested water.In this study,a solid propellant,which consisted of a large percentage...A performance study of a water ramjet engine is described.The engine is powered by the reaction of a magnesium-based propellant and ingested water.In this study,a solid propellant,which consisted of a large percentage of magnesium,a binder and a small amount of oxidant,was used as a hydro reactive fuel.Cold water was injected into the combustion chamber as a main oxidant.A scaled-down experimental engine was tested in a direct-connect ground testing system to characterize the factors influencing the engine performance.The results show that the increasing of total water/fuel ratio,an addition of secondary water intake along the combustion chamber,a larger magnesium content in the solid propellant,a smaller primary water injection angle towards the coming main flow,and a higher primary injection pressure were all able to promote the engine performance.The maximum engine performance was obtained in test 08,and with all tests,an appropriate set of parameters and conditions for the optimum engine performance were determined展开更多
文摘In order to study features of rock–water interaction, a self-developed experimental system called Intelligent Testing System for Water Absorption in Deep Soft Rocks(ITSWADSR) was utilized to analyze the hydrophilic behaviors of natural soft rock at high stress state. Combining X-ray diffraction and mercury injection test, main influencing factors on hydrophilic characteristics were studied. According to the results, it could be concluded as the following:(1) the effective porosity, and the content of illite, illite/smectite formation(S = 5%) and kaolinite have positive correlation with the water absorption capacity of rock; meanwhile, the initial moisture content, fractal dimension of effective pores, illite/smectite formation(S = 30%) and chlorite present negative correlation;(2) among the positive factors, the ascending order is kaolinite, illite/smectite formation(S = 5%) and illite;(3) the descending order among the negative factors are chlorite, illite/smectite formation(S = 30%) and fractal dimension of the effective pores;(4) influence of effective porosity on the pressurized water absorbing capacity of rock is minimal, while it is maximal in the process of no pressurized water absorption.
文摘Research on the Asian-Pacific monsoon has a long history. This paper starts by summarizing field experiments investigating the Asian-Pacific monsoon. Since the 1960s, a number of international and regional monsoon projects and field experiments have been carried out, and substantial progress regarding research on the Asian-Pacific monsoon has been made. Second, the onset and the seasonal march of the Asian summer monsoon and the annual cycle of active and break periods of the monsoon, which are characterized by precipitation maxima and minima, are studied. Since the inter-tropical convergence zone (ITCZ or TCZ) is the dominating weather system and is the major birthplace of typhoons and tropical convective systems, the monsoonal rainfall and ITCZ are analyzed after the onset of the Asian mon- soon. Finally, because the ITCZ has a close relationship with tropical convective systems and rainfall events in monsoon regions, analyses of the developments of deep convection and rainfall events are briefly introduced.
文摘The pull-out capacities for soil nailing systems comprising of one single 29 mm diameter(type A) and four 16 mm diameter(type B) rebars with grouted cement were examined.A field test and numerical analysis for the type A and type B systems were carried out to investigate the pull-out capacities and the slope stability reinforcement efficiency in soil and rock slopes.The results of the pull-out tests show the mobilized shear force and load transfer characteristics with respect to soil depth.The load-displacement relationship was examined for both type A and type B systems.Slope stability analyses were carried out to study the relationships between soil and nail reinforcement and bending stiffness as well as combined axial tension and shear forces.Factors of safety were calculated in relation to the number of nails and their outside diameters.Both soil and rock slopes were included in this evaluation.
文摘Sodium hypochlorite and ozone are the principal active substances and usually employed in ballast water management systems. In the present study, the authors focus on the effect of these active substances to the maaix polymer of coating. In order to obtain such information, the authors investigated the penetration of active substances to the polymer from cross section of specimens introduced by SAICAS (surface and interracial cutting analysis system), followed by FT-IR-ATR (Fourier transform infrared and attenuated total reflectance) spectroscopy analysis from Z direction of cross section. The corrosion test of coating panels by these active substances (control as artificial seawater) has been conducted for 120 days. The results show that the depth profile of each active substance is around few dozens of micrometers from coating surface. The criteria of corrosion test cannot be determined by these results due to lacking in actual corrosion data immersed for 15 years under active substances. However, the authors evaluated the effect on ballast tank coating systems by active substances using analytical methods of SAICAS and FT-IR-ATR spectroscopy.
文摘A series of water absorption tests on dried soft rock have been conducted by the intelligent testing system for water absorption tests in deep soft rock, including tests of water absorption with and without pres- sure. The results show that the water absorbing capacity of rock with a certain pressure is larger than that of rock without pressure: however, the relationship between the water absorbing percentage and the time can be expressed by w(t) = a(l - e^-bt). In hi-logarithmic coordinates, the hydrophilic relationship with time in tests with pressure could be characterized by linearity, while they present concave or convex in tests without pressure. Based on the hypothesis that each influential factor is irrelevant and they have a linear correlation with the water absorbing capacity, we calculated the weight coefficient of each factor according to experimental results under different conditions. The calculations demonstrate that the effec- tive porosity, content of smectite and kaolinite are all positively correlated with the water absorption capacity of rock; meanwhile, the fractal dimension of the effective pores presents a negative correlation with the water absorption capacity of rock. The water absorption capacity with pressure increases with increasing illite, chlorite and chlorite/smectite formation and a decrease in illite/smectite formation and the fractal dimension of the effective pores, while it is opposite in tests without pressure. The weight coefficient of smectite is smallest among positive factors, and the fractal dimension of the effective pores is the smallest amongst the negative factors.
基金Project(2011-0021376) supported by Basic Science Program through the National Research Foundation (NRF) Funded by the Ministry of Education,Science and Technology of Korea
文摘The research goal is to develop a new solar water heater system(SWHS) that uses a solar bubble pump instead of an electric pump.The pump is powered by the steam produced from an evacuated tube collector.Therefore,heat could be transferred downward from the collector to a hot water storage tank.The designed system consists of two sets of heat-pipe evacuated tube collectors,a solar bubble pump installed at an upper level and a water storage tank with a heat exchanger at a lower level.Discharge heads of 1 and 5 m were tested.The bubble pump could operate at the collector temperature of about 90-100 ℃ and vapor gage pressure of 80-90 kPa.It is found that water circulation within the SWHS depends on the incident solar intensity and system discharge head.Experimental investigations are conducted to obtain the system thermal efficiencies from the hourly,daily and long-term performance tests.The thermal performance of the proposed system is compared with conventional solar water heaters.The results show that the proposed system achieves system characteristic efficiency of 10% higher than that of the conventional systems using electric pump if taking the consumption of electric power into account.And the former is a zero carbon system.
文摘Bali Tourism Development Corporation's lagoon (BTDC lagoon) has been used for treating wastewaters that come from all facilities available in the Nusa Dua Resort tourist area. Reuse of the lagoon effluent is limited for some applications due to salt and suspended solid contents. Application of an integrated membrane system for improving the water quality of the lagoon effluent which is suitable for various uses is under consideration. In this work an ultraflltration (UF) pilot performance for possible pretreatment of Reverse Osmosis (RO) was investigated. The results showed that permeate quality was stable (less than 0.5 NTU), regardless of concentrating and diluting retentate in each cycle and fouling for a long duration of operation. However, the water quality obtained with this membrane was not enough to be directly used. The permeate quality obtained from the UF system fulfils the requirement for the optimal operation of reverse osmosis. Moreover, appropriate intermittent-backwash operation was fairly effective to maintain the fluxes at a reasonable level.
文摘In response to the high requirements of industrial precision test, presenting a method of testing relative relation of space points was studied. The spatial-coordinate testing system was established by using high precision theodolites and horizontal staff. The related test was conducted with the use of the space intersection and the precision was evaluated based on the error of baseline. In the practical application of radar-development base, the relative relation of space points was implemented by using electronic theodolite and horizontal staff, which can be easily operated. Furthermore, it can be conveniently used to test small areas where the instruments are difficult to be installed and for high industrial requirements of precision test. The test results can fully meet the strict industrial requirements.
文摘The effluents of textile dyes are highly colored, and disposal of the wastes into receiving waters cause damage to the environment, therefore dyes removal is of great importance. In this research, removal of Orange II, Remazol Blue, Methyl red, Malachite green and Safranin dyes by Pseudomonas fluorescens was studied in batch system as function of temperature, pH and initial dye concentration. The rate of removal dyes was studied by using pectrophotometer. The optimum value was determined as pH 7 for all dyes tested about 87.8-72.7%, and optimum temperature for removal of all tested dyes was 30℃ about 86.6-60.8%. Higher removal of dyes observed at 25 mL for all tested dyes about 91.9-72,7%. In general, the increase in dye concentration inhibited the growth of bacteria. Pseudomonasfluorescens showed higher removal of Orange II among the dyes tested.
文摘This study sought to assess Gweru's water supply system from the source to the consumer to find out whether the water is safe for domestic purposes, mainly consumption. Water samples were taken from Gwenoro dam (raw water), Gwenoro treatment plant (treated water) as well as from GIS-generated random points of residential areas closest to Gwenoro and furthest from both the dam and the treatment plant. These were taken for laboratory testing where parameters like pH, hardness, turbidity and DO (dissolved oxygen) were tested. Questionnaires were used to solicit the views of the consumers on water quality and water service delivery from eight randomly selected residential suburbs. Interviews were also administered to Gwenoro Water Treatment Plant superintendent and deputy to get insight into the day to day challenges that they have to grapple with. Results generally show that treated water from Gwenoro treatment plant is relatively safe to drink for those who have access to it. However, some consumer points like Mkoba 13 and Mkoba 18 receive water whose DO is out of the recommended range. Suburbs which lie on higher ground like Mkoba 19 and Mkoba 14 however rarely receive water from Gwenoro with some residents of Mkoba 19 having had no water from their taps for more than three years now. The study recommends that new equipment be bought for the treatment plant so that treated water reaches all parts of the city. Newly resettled farmers in the Upper Runde Catchment must be resettled elsewhere while urban stream bank cultivation must be banned to reduce water pollution as well as possible sedimentation of Gwenoro dam.
文摘The performance of a BTES (borehole thermal energy storage) system is primarily governed by ground heat flux, soil thermal properties and groundwater conditions. However, the design of the heat exchanger used within the BTES system can also make a significant difference in the efficiency of the system. A thermal response test was carded out for a Kelix GHE (ground heat exchanger) system, the latest innovation in geothermal ground loop construction, on an Ecofarm in the town of Caledon East, Ontario, Canada. In addition, a verifying test was performed for a CEES (conventional earth energy system) located 6 m away from the Kelix GHE. The boreholes for these two different heat exchanger designs were drilled with the same diameter, to the same depth and were located in the same/identical geo-hydrological conditions. The response test provided the effective average of undisturbed ground temperature, geothermal properties including thermal conductivity, heat capacity and thermal resistance between the fluid and the borehole wall. The mathematical analysis method used for the response test is presented here. Results of the response test were verified, analyzed and are further discussed.
文摘This research presents the results of system validation tests for an SOFC power system. In the study, the system was heated up without electric device, i.e., the fuel providing the required thermal energy through an integrated BOP (balance of plant). The ex-situ experiments, without an SOFC stack installed in the system, were fast conducted to investigate the operability of a BOP apparatus. It was found that the BOP possessed high conversion rates for both steam reforming and water gas shift reactions. The total fuel concentration of hydrogen and carbon monoxide from the reformer was around 91.2%. The system validation tests showed that, with the natural gas as fuel, the output power from the stack reached to 1,060 W, while the fuel utilization efficiency and electrical efficiency were 67.16% and 45.0%, respectively. A steady 600-hour system operation test was carried out at an average system temperature of 694℃. Of which, a 36-cell stack was employed for the test. Meanwhile, the current, voltage and output power were 26 A, 32.3 V and 840 W, respectively, and its electrical efficiency was around 33.4%.
基金supported by the National Basic Research Program of China ("973" Program) (Grant No. 61350)
文摘A performance study of a water ramjet engine is described.The engine is powered by the reaction of a magnesium-based propellant and ingested water.In this study,a solid propellant,which consisted of a large percentage of magnesium,a binder and a small amount of oxidant,was used as a hydro reactive fuel.Cold water was injected into the combustion chamber as a main oxidant.A scaled-down experimental engine was tested in a direct-connect ground testing system to characterize the factors influencing the engine performance.The results show that the increasing of total water/fuel ratio,an addition of secondary water intake along the combustion chamber,a larger magnesium content in the solid propellant,a smaller primary water injection angle towards the coming main flow,and a higher primary injection pressure were all able to promote the engine performance.The maximum engine performance was obtained in test 08,and with all tests,an appropriate set of parameters and conditions for the optimum engine performance were determined