Uzu-kuei Hsu - Academia.edu (original) (raw)

Papers by Uzu-kuei Hsu

Research paper thumbnail of Numerical Studies on a NACA0018 Airfoil Blade HAWT with Trailing Edge Jet Flow

E3S web of conferences, 2018

This study analyzed an airfoil blade for a horizontal-axis wind turbine (HAWT) with a trailingedg... more This study analyzed an airfoil blade for a horizontal-axis wind turbine (HAWT) with a trailingedge jet flow design. This design was realized by drilling a hole in the trailing edge of an NACA0018 blade of a conventional HAWT to serve as a pressure injection nozzle. Five inflow wind speeds and three trailingedge jet flow conditions were examined in the test. The results revealed the efficiency differences between a HAWT with the new jet flow design and conventional HAWTs. The experimental methods employed involved a wind tunnel experiment and a computational fluid dynamics (CFD) simulation. The results revealed that when the inflow wind speed was low, the trailing-edge jet flow accelerated the initiation phase and increased the rotating speed of the HAWT; however, when the inflow wind speed was high, damping occurred and the rotating speed of the turbine blades decreased.

Research paper thumbnail of Observation of solid fuel in a supersonic flowfield

WIT transactions on modelling and simulation, Jun 11, 2007

Hypersonic vehicles will be the new-generation of aerial transport. Hence, supersonic combustor d... more Hypersonic vehicles will be the new-generation of aerial transport. Hence, supersonic combustor design becomes important. Many investigations have been conducted on this subject, however, they are focused on gaseous or liquid fuels combustor. The use of a solid fuel combustor can substantially decrease complexity and cost, so for certain purposes, solid fuel supersonic combustors show advantages over other fuel systems. This research adopts a shock tube, 16 meter long and with a bore of 9 cm to create a supersonic, high-temperature, and high-pressure flowfield to observe the gasification and ignition of HTPB solid fuel under different environments. Also, full-scale 3D numerical simulation is executed to enhance the comprehension of this complex phenomenon. The CFD code is based on the control volume method and the pre-conditioning method for solving the Navier-Stokes equations to simulate the compressible and incompressible coupling problem. In the tests, a HTPB slab is placed in the windowed-test section. Various test conditions generate different supersonic Mach numbers and environmental temperatures, meanwhile the HTPB slab changes its incident angles relative to the coming shock wave. Results show that when the Mach number around the slab section is beyond 1.25, the flowfield temperature can achieve above 1100K, which is higher than the HTPB gasification temperature (930K~1090K), then the gasification happens and a short-period ignition can be observed. In particular, as the slab angle is 7°, the phenomenon is more visible. This is due to the flowfield temperature increasing when the slab angle is at 7°. The comparison between test results and CFD simulation show good agreement, so the CFD results help the understanding and analysis of this complicated test event. Several pictures demonstrating the research results are shown below.

Research paper thumbnail of The feasibility strategy to enhance rate of emergency rescue dispatch with optimized way of dressing

Rescue mission against the clock. When people are in urgent distress, the shorter the response ti... more Rescue mission against the clock. When people are in urgent distress, the shorter the response time of rescue personnel, the faster the people who need help would be away from dangerous situation. It also means that the smaller loss of victims, the shorter time the rescue workers are exposed to hazardous environments. Take plane crash for example, the average time to escape is only 90 seconds. Between a few seconds, it may cause the difference between life and death. In the emergency procedure, time of departure is controlled factor. In practice, it is bound to delay the whole rescue mission since the time for dressing is about 30 seconds and to complete the deployment of combat power is more than 180 seconds (Time includes Fire trucks to the scene). Therefore, how to shorten the time to mobilize and salvage is one of the most urgently addressed problems of the rescue mission. This study was to review the rescuers manner of dress. Propose the use of the new-style protective equipment racks which can effectively compress the time to dress and rush to the scene to rescue the victims as soon as possible, put out the fire to complete a high-performance relief operation. Through practical simulation test of the fire service personnel in a military base, it is found that compared to the current common dressing procedures the time of dressing with the new-style protective equipment racks could be saved about 50% to 57%. Thus, a fire clothes racks has high application potential benefits in the emergency mobilization. It is worth to actively promote by the related units to improve the significant persisting problem of rescue.

Research paper thumbnail of Numerical and Experimental Investigation of a Supersonic Flow Field around Solid Fuel on an Inclined Flat Plate

Modelling and Simulation in Engineering, 2009

This research adopts a shock tube 16 meters long and with a 9 cm bore to create a supersonic, hig... more This research adopts a shock tube 16 meters long and with a 9 cm bore to create a supersonic, high-temperature, and high-pressure flowfield to observe the gasification and ignition of HTPB solid fuel under different environments. Also, full-scale 3D numerical simulation is executed to enhance the comprehension of this complex phenomenon. The CFD (Computational Fluid Dynamics) code is based on the control volume method and the pre-conditioning method for solving the Navier-Stokes equations to simulate the compressible and incompressible coupling problem. In the tests, a HTPB slab is placed in the windowed-test section. Various test conditions generate different supersonic Mach numbers and environmental temperatures. In addition, the incident angles of the HTPB slab were changed relative to the incoming shock wave. Results show that as the Mach number around the slab section exceeded 1.25, the flowfield temperature achieved 1100 K, which is higher than the HTPB gasification temperature (930 K ∼ 1090 K). Then, gasification occurred and a short-period ignition could be observed. In particular, when the slab angle was 7 • , the phenomenon became more visible. This is due to the flow field temperature increase when the slab angle was at 7 • .

Research paper thumbnail of The Rotating Flow and Inflow Interaction over a VAWT

Journal of aeronautics, astronautics and aviation, Series A, Mar 1, 2011

In efficiency remains the main problem with VAWT (Vertical Axis Wind Turbine). One method to impr... more In efficiency remains the main problem with VAWT (Vertical Axis Wind Turbine). One method to improve wind turbine efficiency is to reduce the negative moment or increase the positive moment. In this study, five kinds of rotating speeds and three kinds of wind speeds were used to simulate and analyse air flow over a VAWT. The finite volume method with turbulent and sliding mesh models were employed to simulate the flowfield. The results indicate that the separation bubble disappears on the upside of the blade when the blade is rotating into the upwind, and highest differential pressure occurs near to the leading edge of the blade. Moreover, when the differential pressure is higher, the moment is greater, and the moment increases when inflow speed and rotating speed are both increasing. The output moment is similar when the tip speed ratio is identical. The selection of the tip speed radio is 1.25 when the blade chord is 1 and the radius is 2.

Research paper thumbnail of Numerical Studies of the Flowfield for the Taking-off or Hovering of a Small Quadrotor UAV

Journal of aeronautics, astronautics and aviation, Series A, Dec 1, 2015

Research paper thumbnail of Investigation of the Cooling and Uniformity Effectiveness in a Sinter Packed Bed

World Academy of Science, Engineering and Technology, International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering, Mar 2, 2016

Research paper thumbnail of Integrating technology to develop renewable energy to explore a sustainable future for Taiwan by the SECRDC in NPUST

IOP Conference Series: Earth and Environmental Science

To keep the next generation safe from the energy depletion crisis and slow the impact of climate ... more To keep the next generation safe from the energy depletion crisis and slow the impact of climate change. The world is accelerating the energy transition with the goal of net zero emissions. National Pingtung University of Science and Technology / NPUST established a Sustainable Circular Economy R&D Center / SCERDC. To develop innovative technologies and combine green energy applications across fields for the waste materials, waste recycling and energy saving and carbon reduction of agriculture, forestry, fishery and animal husbandry. Add more strength to “circular economy” and “sustainable environment”.

Research paper thumbnail of The feasibility strategy to enhance rate of emergency rescue dispatch with optimized way of dressing

2016 International Conference on Applied System Innovation (ICASI)

Rescue mission against the clock. When people are in urgent distress, the shorter the response ti... more Rescue mission against the clock. When people are in urgent distress, the shorter the response time of rescue personnel, the faster the people who need help would be away from dangerous situation. It also means that the smaller loss of victims, the shorter time the rescue workers are exposed to hazardous environments. Take plane crash for example, the average time to escape is only 90 seconds. Between a few seconds, it may cause the difference between life and death. In the emergency procedure, time of departure is controlled factor. In practice, it is bound to delay the whole rescue mission since the time for dressing is about 30 seconds and to complete the deployment of combat power is more than 180 seconds (Time includes Fire trucks to the scene). Therefore, how to shorten the time to mobilize and salvage is one of the most urgently addressed problems of the rescue mission. This study was to review the rescuers manner of dress. Propose the use of the new-style protective equipment racks which can effectively compress the time to dress and rush to the scene to rescue the victims as soon as possible, put out the fire to complete a high-performance relief operation. Through practical simulation test of the fire service personnel in a military base, it is found that compared to the current common dressing procedures the time of dressing with the new-style protective equipment racks could be saved about 50% to 57%. Thus, a fire clothes racks has high application potential benefits in the emergency mobilization. It is worth to actively promote by the related units to improve the significant persisting problem of rescue.

Research paper thumbnail of Transient studies of a 3D aero-shaped tilting-disc valve in pulsatile flow

2016 International Conference on Applied System Innovation (ICASI), 2016

A new 3D prosthetic valve design method is proposed which fully utilizes the aeronautic wing desi... more A new 3D prosthetic valve design method is proposed which fully utilizes the aeronautic wing design guidelines. The design objective of this aero-shaped valve (ASV) aims at lowering the valve-induced blood damage and minimizing the impact momentum between occluder and valve strut. Unlike the past valve designs which relied on trial-and-error process, the present design uses analytic methods and stresses the transvalvular flowfield quality. Not only occluder configuration is examined in detail, but the influence of pivot location is accounted for. Based on the theory of wing sections and the analogy of flight stability, a concurrent occluder shape and rotation center optimization is accomplished. This optimization procedure, which integrates Computational Fluid Dynamics (CFD), Artificial Neural Network (ANN), and Genetic Algorithm (GA), is developed to search for a low-thrombogenic occluder shape and a permissible rotating center position. Comparing the optimized ASV to the conventional plate-like occluders, ASV encompasses better hemodynamic characteristics in terms of lower transvalvular pressure gradient and turbulence Reynolds stresses.

Research paper thumbnail of Unsteady Simulation Of Burning Off Carbon Deposition In A Coke Oven

Carbon Deposits are often occurred inside the<br> industrial coke oven during coking proces... more Carbon Deposits are often occurred inside the<br> industrial coke oven during coking process. Accumulation of carbon<br> deposits may cause a big issue, which seriously influences the coking<br> operation. The carbon is burning off by injecting fresh air through<br> pipes into coke oven which is an efficient way practically operated in<br> industries. The burning off carbon deposition in coke oven performed<br> by Computational Fluid Dynamics (CFD) method has provided an<br> evaluation of the feasibility study. A three dimensional, transient,<br> turbulent reacting flow simulation has performed with three different<br> injecting air flow rate and another kind of injecting configuration. The<br> result shows that injection higher air flow rate would effectively<br> reduce the carbon deposits. In the meantime, the opened charging<br> holes would suck extra oxygen from atmosphere to participate in<br> reactio...

Research paper thumbnail of New Concept For The Overall Use Of Renewable Energy

The development and application of wind power for renewable energy has attracted growing interest... more The development and application of wind power for renewable energy has attracted growing interest in recent years. Renewable energy sources are attracting much alteration as they can reduce both environmental damage and dependence on fossil fuels. With the growing need for sustainable energy supplies, a case is made for decentralized, stand-alone power supplies (SAPS) as an alternative to power grids. In the era which traditional petroleum energy resource decreasing and the green house affect significant increasing, the development and usage of regenerative resources is inevitable. Due to the contribution of the pioneers, the development of regenerative resources already has a remarkable achievement; however, in the view of economy and quantity, it is still a long road for regenerative energy to replace traditional petroleum energy. In our prospective, in stead of investigate larger regenerative energy equipment, it is much wiser to think about the blind side and breakthrough of the...

Research paper thumbnail of Investigation Of The Cooling And Uniformity Effectiveness In A Sinter Packed Bed

When sinters are filled into the cooler from the sintering machine, and the non-uniform distribut... more When sinters are filled into the cooler from the sintering machine, and the non-uniform distribution of the sinters leads to uneven cooling. This causes the temperature difference of the sinters leaving the cooler to be so large that it results in the conveyors being deformed by the heat. The present work applies CFD method to investigate the thermo flowfield phenomena in a sinter cooler by the Porous Media Model. Using the obtained experimental data to simulate porosity (Ε), permeability (κ), inertial coefficient (F), specific heat (Cp) and effective thermal conductivity (keff) of the sinter packed beds. The physical model is a similar geometry whose Darcy numbers (Da) are similar to the sinter cooler. Using the Cooling Index (CI) and Uniformity Index (UI) to analyze the thermo flowfield in the sinter packed bed obtains the cooling performance of the sinter cooler.

Research paper thumbnail of Study on the mechanical property of cement-based composites with the addition of iron sand

2018 IEEE International Conference on Applied System Invention (ICASI), 2018

This study is a preliminary test for children's game wall, in which recycled scrap iron conta... more This study is a preliminary test for children's game wall, in which recycled scrap iron containers and other scrap iron, crushed, paint, and other procedures are mixed with cement concrete to replace the aggregate. This follows the curing of cement-based iron sand concrete magnetic adsorption properties. Because, compressive strength is important for concrete, this study determines the compressive strength of concrete that contains iron sand, which can be adsorbed by magnets, by using recycled scrap iron containers and other scrap iron. The test variables include 7-day, 14-day, and 28-day compressive strength. The water to cement (W/C) ratio is 0.5, and the iron sand replacement rates run from 0% to 60%. The result shows that when 10% of iron sand is used as a substitute to find aggregates, it has the highest compressive strength and has magnetic adsorption.

Research paper thumbnail of Numerical studies of the unsteady flowfield over a mems thermal film boundary in pulsatile flow

Research paper thumbnail of Observation of solid fuel in a supersonic flowfield

WIT Transactions on Modelling and Simulation, Vol 46, 2007

Hypersonic vehicles will be the new-generation of aerial transport. Hence, supersonic combustor d... more Hypersonic vehicles will be the new-generation of aerial transport. Hence, supersonic combustor design becomes important. Many investigations have been conducted on this subject, however, they are focused on gaseous or liquid fuels combustor. The use of a solid fuel combustor can substantially decrease complexity and cost, so for certain purposes, solid fuel supersonic combustors show advantages over other fuel systems. This research adopts a shock tube, 16 meter long and with a bore of 9 cm to create a supersonic, high-temperature, and high-pressure flowfield to observe the gasification and ignition of HTPB solid fuel under different environments. Also, full-scale 3D numerical simulation is executed to enhance the comprehension of this complex phenomenon. The CFD code is based on the control volume method and the pre-conditioning method for solving the Navier-Stokes equations to simulate the compressible and incompressible coupling problem. In the tests, a HTPB slab is placed in the windowed-test section. Various test conditions generate different supersonic Mach numbers and environmental temperatures, meanwhile the HTPB slab changes its incident angles relative to the coming shock wave. Results show that when the Mach number around the slab section is beyond 1.25, the flowfield temperature can achieve above 1100K, which is higher than the HTPB gasification temperature (930K~1090K), then the gasification happens and a short-period ignition can be observed. In particular, as the slab angle is 7°, the phenomenon is more visible. This is due to the flowfield temperature increasing when the slab angle is at 7°. The comparison between test results and CFD simulation show good agreement, so the CFD results help the understanding and analysis of this complicated test event. Several pictures demonstrating the research results are shown below.

Research paper thumbnail of Low Reynolds Number Unsteady Aerodynamic Characteristics of Flapping Corrugated Airfoil

The development of biomimetic flapping wing microaerial-vehicles (MAVs) is the future trend in mi... more The development of biomimetic flapping wing microaerial-vehicles (MAVs) is the future trend in military/domestic field. The successful flight of MAVs is strongly related to the understanding of unsteady aerodynamic performance of low Reynolds number airfoils under dynamic flapping motion. This study explored the effects of flapping frequency, stroke amplitude, and the inclined angle of stroke plane on lift force and thrust force of a corrugated airfoil with 3 full factorial design of experiment and ANOVA analysis. Unsteady vorticity flows over a corrugated airfoil executing flapping motion are computed with timedependent two-dimensional laminar Reynolds-averaged Navier-Stokes equations with the conformal hybrid mesh. The tested freestream Reynolds number based on the chord length of airfoil as characteristic length is fixed of 10. The dynamic mesh technique is applied to model the flapping motion of a corrugated airfoil. Instant vorticity contours over a complete flapping cycle clea...

Research paper thumbnail of Numerical studies of the turbulent planar mixing layer using nonlinear k-ε model

Research paper thumbnail of Numerical studies on a vertical tubular wind collector with backward-facing step outlet

2018 IEEE International Conference on Applied System Invention (ICASI), 2018

This paper carried out a new concept design of wind collection, a vertical tubular wind collector... more This paper carried out a new concept design of wind collection, a vertical tubular wind collector. Using two key-point design: backed-forcing step and cylindering flow design the structure of main body. The finite volume method is applied to solve the Navier-Stokes equations, and the steady-state flow field analysis is simulated with the realizable k-ε turbulence model. The height of the exit groove is changed (0D ∼ 4D), and the effects of different inlet wind speed (5m/s ∼ 12.5m / s) on the inlet were discussed. The result shows that increasing the groove cutting height increases the local low pressure zone at the outlet, and the low pressure vortex increases. The suction effect is the best while the cylindrical rear produces a stable symmetrical vortex system.

Research paper thumbnail of Numerical Study on Flow Field for a Solar Collector at Various Inflow Incidence Angles

Journal of aeronautics, astronautics and aviation, Series A, 2014

Previous studies on solar water heaters (SWHs) have primarily focused on the thermal efficiency o... more Previous studies on solar water heaters (SWHs) have primarily focused on the thermal efficiency of a solar collector and structural safety. This study applied a numerical simulation method to examine the characteristics of flowfield. In addition, a solar collector of a SWH was employed to investigate the distribution of average surface pressure and vortex structure for various inflow incidence angles as well as the influence of two types of spoiler. This study adopted a computational fluid dynamics fluid mechanics method, an incompressible flow algorithm (i.e., semi-implicit method for pressure-linked equation [SIMPLE]), to simulate the flow field of the solar collector. A turbulence model (realizable k-e model) was adopted. The obtained numerical values were compared with the experimental results. Because the simulation data were approximated to the experimental results, the turbulence strength and length were set as 11.7% and 0.12, respectively. The parameter for this study was in...

Research paper thumbnail of Numerical Studies on a NACA0018 Airfoil Blade HAWT with Trailing Edge Jet Flow

E3S web of conferences, 2018

This study analyzed an airfoil blade for a horizontal-axis wind turbine (HAWT) with a trailingedg... more This study analyzed an airfoil blade for a horizontal-axis wind turbine (HAWT) with a trailingedge jet flow design. This design was realized by drilling a hole in the trailing edge of an NACA0018 blade of a conventional HAWT to serve as a pressure injection nozzle. Five inflow wind speeds and three trailingedge jet flow conditions were examined in the test. The results revealed the efficiency differences between a HAWT with the new jet flow design and conventional HAWTs. The experimental methods employed involved a wind tunnel experiment and a computational fluid dynamics (CFD) simulation. The results revealed that when the inflow wind speed was low, the trailing-edge jet flow accelerated the initiation phase and increased the rotating speed of the HAWT; however, when the inflow wind speed was high, damping occurred and the rotating speed of the turbine blades decreased.

Research paper thumbnail of Observation of solid fuel in a supersonic flowfield

WIT transactions on modelling and simulation, Jun 11, 2007

Hypersonic vehicles will be the new-generation of aerial transport. Hence, supersonic combustor d... more Hypersonic vehicles will be the new-generation of aerial transport. Hence, supersonic combustor design becomes important. Many investigations have been conducted on this subject, however, they are focused on gaseous or liquid fuels combustor. The use of a solid fuel combustor can substantially decrease complexity and cost, so for certain purposes, solid fuel supersonic combustors show advantages over other fuel systems. This research adopts a shock tube, 16 meter long and with a bore of 9 cm to create a supersonic, high-temperature, and high-pressure flowfield to observe the gasification and ignition of HTPB solid fuel under different environments. Also, full-scale 3D numerical simulation is executed to enhance the comprehension of this complex phenomenon. The CFD code is based on the control volume method and the pre-conditioning method for solving the Navier-Stokes equations to simulate the compressible and incompressible coupling problem. In the tests, a HTPB slab is placed in the windowed-test section. Various test conditions generate different supersonic Mach numbers and environmental temperatures, meanwhile the HTPB slab changes its incident angles relative to the coming shock wave. Results show that when the Mach number around the slab section is beyond 1.25, the flowfield temperature can achieve above 1100K, which is higher than the HTPB gasification temperature (930K~1090K), then the gasification happens and a short-period ignition can be observed. In particular, as the slab angle is 7°, the phenomenon is more visible. This is due to the flowfield temperature increasing when the slab angle is at 7°. The comparison between test results and CFD simulation show good agreement, so the CFD results help the understanding and analysis of this complicated test event. Several pictures demonstrating the research results are shown below.

Research paper thumbnail of The feasibility strategy to enhance rate of emergency rescue dispatch with optimized way of dressing

Rescue mission against the clock. When people are in urgent distress, the shorter the response ti... more Rescue mission against the clock. When people are in urgent distress, the shorter the response time of rescue personnel, the faster the people who need help would be away from dangerous situation. It also means that the smaller loss of victims, the shorter time the rescue workers are exposed to hazardous environments. Take plane crash for example, the average time to escape is only 90 seconds. Between a few seconds, it may cause the difference between life and death. In the emergency procedure, time of departure is controlled factor. In practice, it is bound to delay the whole rescue mission since the time for dressing is about 30 seconds and to complete the deployment of combat power is more than 180 seconds (Time includes Fire trucks to the scene). Therefore, how to shorten the time to mobilize and salvage is one of the most urgently addressed problems of the rescue mission. This study was to review the rescuers manner of dress. Propose the use of the new-style protective equipment racks which can effectively compress the time to dress and rush to the scene to rescue the victims as soon as possible, put out the fire to complete a high-performance relief operation. Through practical simulation test of the fire service personnel in a military base, it is found that compared to the current common dressing procedures the time of dressing with the new-style protective equipment racks could be saved about 50% to 57%. Thus, a fire clothes racks has high application potential benefits in the emergency mobilization. It is worth to actively promote by the related units to improve the significant persisting problem of rescue.

Research paper thumbnail of Numerical and Experimental Investigation of a Supersonic Flow Field around Solid Fuel on an Inclined Flat Plate

Modelling and Simulation in Engineering, 2009

This research adopts a shock tube 16 meters long and with a 9 cm bore to create a supersonic, hig... more This research adopts a shock tube 16 meters long and with a 9 cm bore to create a supersonic, high-temperature, and high-pressure flowfield to observe the gasification and ignition of HTPB solid fuel under different environments. Also, full-scale 3D numerical simulation is executed to enhance the comprehension of this complex phenomenon. The CFD (Computational Fluid Dynamics) code is based on the control volume method and the pre-conditioning method for solving the Navier-Stokes equations to simulate the compressible and incompressible coupling problem. In the tests, a HTPB slab is placed in the windowed-test section. Various test conditions generate different supersonic Mach numbers and environmental temperatures. In addition, the incident angles of the HTPB slab were changed relative to the incoming shock wave. Results show that as the Mach number around the slab section exceeded 1.25, the flowfield temperature achieved 1100 K, which is higher than the HTPB gasification temperature (930 K ∼ 1090 K). Then, gasification occurred and a short-period ignition could be observed. In particular, when the slab angle was 7 • , the phenomenon became more visible. This is due to the flow field temperature increase when the slab angle was at 7 • .

Research paper thumbnail of The Rotating Flow and Inflow Interaction over a VAWT

Journal of aeronautics, astronautics and aviation, Series A, Mar 1, 2011

In efficiency remains the main problem with VAWT (Vertical Axis Wind Turbine). One method to impr... more In efficiency remains the main problem with VAWT (Vertical Axis Wind Turbine). One method to improve wind turbine efficiency is to reduce the negative moment or increase the positive moment. In this study, five kinds of rotating speeds and three kinds of wind speeds were used to simulate and analyse air flow over a VAWT. The finite volume method with turbulent and sliding mesh models were employed to simulate the flowfield. The results indicate that the separation bubble disappears on the upside of the blade when the blade is rotating into the upwind, and highest differential pressure occurs near to the leading edge of the blade. Moreover, when the differential pressure is higher, the moment is greater, and the moment increases when inflow speed and rotating speed are both increasing. The output moment is similar when the tip speed ratio is identical. The selection of the tip speed radio is 1.25 when the blade chord is 1 and the radius is 2.

Research paper thumbnail of Numerical Studies of the Flowfield for the Taking-off or Hovering of a Small Quadrotor UAV

Journal of aeronautics, astronautics and aviation, Series A, Dec 1, 2015

Research paper thumbnail of Investigation of the Cooling and Uniformity Effectiveness in a Sinter Packed Bed

World Academy of Science, Engineering and Technology, International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering, Mar 2, 2016

Research paper thumbnail of Integrating technology to develop renewable energy to explore a sustainable future for Taiwan by the SECRDC in NPUST

IOP Conference Series: Earth and Environmental Science

To keep the next generation safe from the energy depletion crisis and slow the impact of climate ... more To keep the next generation safe from the energy depletion crisis and slow the impact of climate change. The world is accelerating the energy transition with the goal of net zero emissions. National Pingtung University of Science and Technology / NPUST established a Sustainable Circular Economy R&D Center / SCERDC. To develop innovative technologies and combine green energy applications across fields for the waste materials, waste recycling and energy saving and carbon reduction of agriculture, forestry, fishery and animal husbandry. Add more strength to “circular economy” and “sustainable environment”.

Research paper thumbnail of The feasibility strategy to enhance rate of emergency rescue dispatch with optimized way of dressing

2016 International Conference on Applied System Innovation (ICASI)

Rescue mission against the clock. When people are in urgent distress, the shorter the response ti... more Rescue mission against the clock. When people are in urgent distress, the shorter the response time of rescue personnel, the faster the people who need help would be away from dangerous situation. It also means that the smaller loss of victims, the shorter time the rescue workers are exposed to hazardous environments. Take plane crash for example, the average time to escape is only 90 seconds. Between a few seconds, it may cause the difference between life and death. In the emergency procedure, time of departure is controlled factor. In practice, it is bound to delay the whole rescue mission since the time for dressing is about 30 seconds and to complete the deployment of combat power is more than 180 seconds (Time includes Fire trucks to the scene). Therefore, how to shorten the time to mobilize and salvage is one of the most urgently addressed problems of the rescue mission. This study was to review the rescuers manner of dress. Propose the use of the new-style protective equipment racks which can effectively compress the time to dress and rush to the scene to rescue the victims as soon as possible, put out the fire to complete a high-performance relief operation. Through practical simulation test of the fire service personnel in a military base, it is found that compared to the current common dressing procedures the time of dressing with the new-style protective equipment racks could be saved about 50% to 57%. Thus, a fire clothes racks has high application potential benefits in the emergency mobilization. It is worth to actively promote by the related units to improve the significant persisting problem of rescue.

Research paper thumbnail of Transient studies of a 3D aero-shaped tilting-disc valve in pulsatile flow

2016 International Conference on Applied System Innovation (ICASI), 2016

A new 3D prosthetic valve design method is proposed which fully utilizes the aeronautic wing desi... more A new 3D prosthetic valve design method is proposed which fully utilizes the aeronautic wing design guidelines. The design objective of this aero-shaped valve (ASV) aims at lowering the valve-induced blood damage and minimizing the impact momentum between occluder and valve strut. Unlike the past valve designs which relied on trial-and-error process, the present design uses analytic methods and stresses the transvalvular flowfield quality. Not only occluder configuration is examined in detail, but the influence of pivot location is accounted for. Based on the theory of wing sections and the analogy of flight stability, a concurrent occluder shape and rotation center optimization is accomplished. This optimization procedure, which integrates Computational Fluid Dynamics (CFD), Artificial Neural Network (ANN), and Genetic Algorithm (GA), is developed to search for a low-thrombogenic occluder shape and a permissible rotating center position. Comparing the optimized ASV to the conventional plate-like occluders, ASV encompasses better hemodynamic characteristics in terms of lower transvalvular pressure gradient and turbulence Reynolds stresses.

Research paper thumbnail of Unsteady Simulation Of Burning Off Carbon Deposition In A Coke Oven

Carbon Deposits are often occurred inside the<br> industrial coke oven during coking proces... more Carbon Deposits are often occurred inside the<br> industrial coke oven during coking process. Accumulation of carbon<br> deposits may cause a big issue, which seriously influences the coking<br> operation. The carbon is burning off by injecting fresh air through<br> pipes into coke oven which is an efficient way practically operated in<br> industries. The burning off carbon deposition in coke oven performed<br> by Computational Fluid Dynamics (CFD) method has provided an<br> evaluation of the feasibility study. A three dimensional, transient,<br> turbulent reacting flow simulation has performed with three different<br> injecting air flow rate and another kind of injecting configuration. The<br> result shows that injection higher air flow rate would effectively<br> reduce the carbon deposits. In the meantime, the opened charging<br> holes would suck extra oxygen from atmosphere to participate in<br> reactio...

Research paper thumbnail of New Concept For The Overall Use Of Renewable Energy

The development and application of wind power for renewable energy has attracted growing interest... more The development and application of wind power for renewable energy has attracted growing interest in recent years. Renewable energy sources are attracting much alteration as they can reduce both environmental damage and dependence on fossil fuels. With the growing need for sustainable energy supplies, a case is made for decentralized, stand-alone power supplies (SAPS) as an alternative to power grids. In the era which traditional petroleum energy resource decreasing and the green house affect significant increasing, the development and usage of regenerative resources is inevitable. Due to the contribution of the pioneers, the development of regenerative resources already has a remarkable achievement; however, in the view of economy and quantity, it is still a long road for regenerative energy to replace traditional petroleum energy. In our prospective, in stead of investigate larger regenerative energy equipment, it is much wiser to think about the blind side and breakthrough of the...

Research paper thumbnail of Investigation Of The Cooling And Uniformity Effectiveness In A Sinter Packed Bed

When sinters are filled into the cooler from the sintering machine, and the non-uniform distribut... more When sinters are filled into the cooler from the sintering machine, and the non-uniform distribution of the sinters leads to uneven cooling. This causes the temperature difference of the sinters leaving the cooler to be so large that it results in the conveyors being deformed by the heat. The present work applies CFD method to investigate the thermo flowfield phenomena in a sinter cooler by the Porous Media Model. Using the obtained experimental data to simulate porosity (Ε), permeability (κ), inertial coefficient (F), specific heat (Cp) and effective thermal conductivity (keff) of the sinter packed beds. The physical model is a similar geometry whose Darcy numbers (Da) are similar to the sinter cooler. Using the Cooling Index (CI) and Uniformity Index (UI) to analyze the thermo flowfield in the sinter packed bed obtains the cooling performance of the sinter cooler.

Research paper thumbnail of Study on the mechanical property of cement-based composites with the addition of iron sand

2018 IEEE International Conference on Applied System Invention (ICASI), 2018

This study is a preliminary test for children's game wall, in which recycled scrap iron conta... more This study is a preliminary test for children's game wall, in which recycled scrap iron containers and other scrap iron, crushed, paint, and other procedures are mixed with cement concrete to replace the aggregate. This follows the curing of cement-based iron sand concrete magnetic adsorption properties. Because, compressive strength is important for concrete, this study determines the compressive strength of concrete that contains iron sand, which can be adsorbed by magnets, by using recycled scrap iron containers and other scrap iron. The test variables include 7-day, 14-day, and 28-day compressive strength. The water to cement (W/C) ratio is 0.5, and the iron sand replacement rates run from 0% to 60%. The result shows that when 10% of iron sand is used as a substitute to find aggregates, it has the highest compressive strength and has magnetic adsorption.

Research paper thumbnail of Numerical studies of the unsteady flowfield over a mems thermal film boundary in pulsatile flow

Research paper thumbnail of Observation of solid fuel in a supersonic flowfield

WIT Transactions on Modelling and Simulation, Vol 46, 2007

Hypersonic vehicles will be the new-generation of aerial transport. Hence, supersonic combustor d... more Hypersonic vehicles will be the new-generation of aerial transport. Hence, supersonic combustor design becomes important. Many investigations have been conducted on this subject, however, they are focused on gaseous or liquid fuels combustor. The use of a solid fuel combustor can substantially decrease complexity and cost, so for certain purposes, solid fuel supersonic combustors show advantages over other fuel systems. This research adopts a shock tube, 16 meter long and with a bore of 9 cm to create a supersonic, high-temperature, and high-pressure flowfield to observe the gasification and ignition of HTPB solid fuel under different environments. Also, full-scale 3D numerical simulation is executed to enhance the comprehension of this complex phenomenon. The CFD code is based on the control volume method and the pre-conditioning method for solving the Navier-Stokes equations to simulate the compressible and incompressible coupling problem. In the tests, a HTPB slab is placed in the windowed-test section. Various test conditions generate different supersonic Mach numbers and environmental temperatures, meanwhile the HTPB slab changes its incident angles relative to the coming shock wave. Results show that when the Mach number around the slab section is beyond 1.25, the flowfield temperature can achieve above 1100K, which is higher than the HTPB gasification temperature (930K~1090K), then the gasification happens and a short-period ignition can be observed. In particular, as the slab angle is 7°, the phenomenon is more visible. This is due to the flowfield temperature increasing when the slab angle is at 7°. The comparison between test results and CFD simulation show good agreement, so the CFD results help the understanding and analysis of this complicated test event. Several pictures demonstrating the research results are shown below.

Research paper thumbnail of Low Reynolds Number Unsteady Aerodynamic Characteristics of Flapping Corrugated Airfoil

The development of biomimetic flapping wing microaerial-vehicles (MAVs) is the future trend in mi... more The development of biomimetic flapping wing microaerial-vehicles (MAVs) is the future trend in military/domestic field. The successful flight of MAVs is strongly related to the understanding of unsteady aerodynamic performance of low Reynolds number airfoils under dynamic flapping motion. This study explored the effects of flapping frequency, stroke amplitude, and the inclined angle of stroke plane on lift force and thrust force of a corrugated airfoil with 3 full factorial design of experiment and ANOVA analysis. Unsteady vorticity flows over a corrugated airfoil executing flapping motion are computed with timedependent two-dimensional laminar Reynolds-averaged Navier-Stokes equations with the conformal hybrid mesh. The tested freestream Reynolds number based on the chord length of airfoil as characteristic length is fixed of 10. The dynamic mesh technique is applied to model the flapping motion of a corrugated airfoil. Instant vorticity contours over a complete flapping cycle clea...

Research paper thumbnail of Numerical studies of the turbulent planar mixing layer using nonlinear k-ε model

Research paper thumbnail of Numerical studies on a vertical tubular wind collector with backward-facing step outlet

2018 IEEE International Conference on Applied System Invention (ICASI), 2018

This paper carried out a new concept design of wind collection, a vertical tubular wind collector... more This paper carried out a new concept design of wind collection, a vertical tubular wind collector. Using two key-point design: backed-forcing step and cylindering flow design the structure of main body. The finite volume method is applied to solve the Navier-Stokes equations, and the steady-state flow field analysis is simulated with the realizable k-ε turbulence model. The height of the exit groove is changed (0D ∼ 4D), and the effects of different inlet wind speed (5m/s ∼ 12.5m / s) on the inlet were discussed. The result shows that increasing the groove cutting height increases the local low pressure zone at the outlet, and the low pressure vortex increases. The suction effect is the best while the cylindrical rear produces a stable symmetrical vortex system.

Research paper thumbnail of Numerical Study on Flow Field for a Solar Collector at Various Inflow Incidence Angles

Journal of aeronautics, astronautics and aviation, Series A, 2014

Previous studies on solar water heaters (SWHs) have primarily focused on the thermal efficiency o... more Previous studies on solar water heaters (SWHs) have primarily focused on the thermal efficiency of a solar collector and structural safety. This study applied a numerical simulation method to examine the characteristics of flowfield. In addition, a solar collector of a SWH was employed to investigate the distribution of average surface pressure and vortex structure for various inflow incidence angles as well as the influence of two types of spoiler. This study adopted a computational fluid dynamics fluid mechanics method, an incompressible flow algorithm (i.e., semi-implicit method for pressure-linked equation [SIMPLE]), to simulate the flow field of the solar collector. A turbulence model (realizable k-e model) was adopted. The obtained numerical values were compared with the experimental results. Because the simulation data were approximated to the experimental results, the turbulence strength and length were set as 11.7% and 0.12, respectively. The parameter for this study was in...