Papers by Keyword: Design

Abstract: In machining of difficult-to-cut materials, increase of temperature in tool tip is one of the main reasons resulting in short tool life. Heat can promote adhesion wear and diffusion wear at rake face, accelerate thermal plastic deformation. Furthermore, heat could also accelerate flank wear and promote adhesion wear at flank face. As a result, machining precision of tool will become worse. The common method applied to reduce temperature of tool tip is cutting with coolant supply. Conventional coolant supply is only effective to cool down areas around cutting zone with low pressure when cutting speed is low. When higher cutting heat is generated, the fluid can be vaporized to form a high-temperature steam barrier and most of the fluid suppled does not penetrate in the area adjacent to cutting zone. However, high pressure coolant might overcome the disabilities of flood coolant in milling. Present relevant research focused on effect of ultra-high pressure coolant (UHPC) on rake face mainly. In this study, to improve the machining efficiency (processing time) by using end mill, a prototype of end mill with internal coolant nozzles (both rake side and flank side) was designed and CFD (Computational Fluid Dynamics) simulations were conducted to find out the relatively effective coolant supply method for coolant penetrating in cutting zone of flank face mainly. Beyond that, effects of UHPC on rake face were also examined. During the latest experiments, tool wears, cutting length and roughness of work material were measured under both dry and wet cutting conditions. For wet cutting, three kinds of coolant supply method were applied: flank face only, rake face only and both rake face and flank face. For each method, coolant was supplied under the pressure of 3MPa, 7MPa, 14MPa and 20MPa. Tool wear was significantly reduced, and roughness was improved by high pressure coolant supply.

Abstract: Resistance spot welding (RSW) is a commonly used process in a variety of fields such as automotive, aerospace, household, furniture, and railway for welding sheet metal parts. These industries further demand a welding machine that is portable and versatile in terms of where it can be utilized, such as, among others, remote locations, and is cost and energy-efficient, reliable, and highly efficient performance-wise. With this aim, the work develops a portable spot-welding machine with specific specifications, of an electrode of 0.394 inches in diameter and 10 inches in length, made of copper, and transformer specifications of 6 V-1500 A with 7 variable current settings. This machine is designed to provide accurate, consistent, and reliable welding readings. Additionally, the machine works on an AC supply of 220 volts, making it easily usable. The machine is found to be cost-effective, with a development cost of only 6100 rupees. It has also been found to be reliable and effective in welding up to two 3 mm mild steel plates under different currents, resistivity, and voltage settings. The machine is simple to operate and user-friendly and with a compact and lightweight design, it is highly versatile and easy to operate for a wide range of welding applications.

Abstract: This study focuses on the design and construction of an improved crushing machine with a capacity of 0.15 (150 kg/hr) tons per hour, 15 Hp, and 2910 rpm speed. The design follows criterion design guidelines to ensure the improved service life of the component. When the values produced from the current design approach were contrasted with the values and outcomes received from the analysis using the Ansys package, the design should be reliable. The hammers produced are subjected to carburisation process using bio-wastes such as coconut shells, saw dust, and palm kernel shells to enhance the reliability of the machine. The bending of the shaft is controlled during the rotation at rated speed rpm when a load is applied to the shaft. The critical speed of the shaft is experienced with deflection when the shaft rotates freely. The natural frequency and speed were put under check in order to avoid failure. The von Mises stress was employed as a yielding criterion for the shaft. It states that if the components of stress operating on a body are more than the criterion, the body will yield.

Abstract: An acetabular implant is a cup-shaped implant that wraps around the head of the femur at the hip joint. Severe damage to the acetabular implant results in bone turnover. To meet the needs of implants, appropriate implant manufacturing techniques are needed. Investment casting is the most widely used casting method because it has the best dimensional accuracy. To help reduce production costs in the industry, this research was carried out using the ProCast 2018 Software. In this study using the 2018 ProCast Software with investment casting techniques with CoCrMo material and variations in the orientation of the mold pattern, namely 0^o, 45^o, 90^o and variations in the shape of the sprue including straight sprue , tapper sprue, and reverse tapper sprue. From these variations, the most optimal result is the tapper sppue variation with 0^o print pattern orientation. With the results of the analysis related to the temperature distribution that occurs, fluidity, solidification process and the most optimal shrinkage porosity.

Abstract: Comfort, protection and similar characteristics, which have become imperative for the production of sportswear materials, constantly encourage the textile industry and researchers to search for new innovative solutions. Recently, there are three main areas that scientists focus on - comfort, functionality and aesthetic appeal of sportswear. For the purpose of this research, a set of novel yarns is selected and used to design knitted materials intended for the production of functional sportswear. In this paper the changes in the material properties due to the use of different novel yarn compositions are observed. Regarding the material properties, the mass loss due to the material abrasion, and water vapour transfer rate were measured and analysed. The results of the investigation indicated that the material with the lowest mass, thickness and densities (both horizontal and vertical) exhibit the lowest decrease of mass due to abrasion. The highest decrease of mass is confirmed for the most compact material composed of viscose, polyester standard and elastane. It was further confirmed that the highest water vapour transfer rate exhibits the material that has the lowest density.

Abstract: The prototype of the compressed air foam system was improved based on the evaluation of the numerical parameters obtained with the help of the developed mathematical model of the foam generation process and the pneumatic-hydraulic scheme. The prototype provides the possibility of foam generation both in autonomous mode, due to the installation of cylinders with compressed gas, and in stationary mode, due to the supply of compressed air from an external source. This allows the use of an improved model of the compressed air foam system both in stationary mode (dry pipes, gas stations, etc.) and for use on heavy and light fire trucks, which is important for large cities. Testing of the improved prototype of the system for extinguishing model fires was carried out. The system provides extinguishing of model fires of class 183 B and 144 B when using both a general-purpose foaming agent and a special film-forming foaming agent. When using a film-forming foaming agent, the extinguishing time was reduced by 1.75 times, the consumption of fire extinguishing solution by 1.47 times. But at the same time, it should be taken into account that the cost of the film-forming foaming agent Sofir (sofirafff 6 %) is more than 3.2 times the cost of the general-purpose foaming agent Sofir. The effectiveness of the improved model in extinguishing class A fires was also confirmed. The autonomous compressed air foam system ensures extinguishing of a class 4 A model fire in 90 seconds. Dry foam with a factor of 14 is noted to be more effective in extinguishing solid combustible substances.

Abstract: The issue of providing healthy movement for patients with lower limb amputations requires using of a well-designed lower limb prosthesis. The purpose of this work is to boost the passive prosthesis to a microcontroller-based prosthesis to provide a rotational speed that suits the function for which it is used, the boost focuses on providing a knee mechanism design by using Maxon EC motor, a socket and foot that can be obtained from previous designs. The study required to be achieved some of the basic criteria, as the proposed knee joint must have sufficient strength to bear up the weight of the amputee’s body and also have the ability to flex the knee to 900.The single parts of the knee joint was designed by using Solid Works software. The mechanism of the knee joint will be simulated after assembling each part of the design for envisage the motion of the knee prosthesis. Three materials were selected, taking into account the properties of these materials, Aluminum alloy 6061T6, Aluminum alloy 2024 and AISI4130 Steel. To find out whether the proposed model can withstand the loads, Finite element analysis using (ANSYS computer program software) the results were discussed and the model was evaluated.

Abstract: Photovoltaic solar energy is an abundant, renewable, and clean source of energy that can contribute to the energy transition. However, traditional land-based solar installation have limitations in terms of space, efficiency, and environmental impact. Floating solar panels have emerged as a promising technology that can overcome these limitations and provide a range of benefits. This work describes the design and experimental testing of a small-scale of floating photovoltaic module prototype, with a focus on the effect of solar irradiation on its maximum power output. The prototype is composed of a 4Wp photovoltaic module and a buoyant supporting structure. Using Matlab®, simulations were performed on the floating photovoltaic module under varying environmental conditions, including solar irradiance, temperature, and wind speed. The prototype demonstrated an electrical performance of 3.62W under solar irradiation of 895W/m² and a temperature of 41°C, with a power ratio exceeding 97% of this maximum power under standard conditions. The prototype also showed a positive energy gain when compared to the same photovoltaic module in a horizontal or inclined position, particularly at high temperature and solar irradiance. Moreover, shows a stability and resistance in harsh weather conditions. The mathematical fitting with a Gaussian distribution shows the rapid increase of the maximum power of the floating photovoltaic module in the range of 37°C to 42°C of temperature with increasing solar irradiance.

Abstract: As climate change effect on our daily life is clear, and the awareness of greenhouse gases damages is increased, architects and many developers necessitate green and sustainable buildings design by focusing on energy efficiency, avoiding harmful materials, and taking care of indoor air quality to construct environmentally friend buildings. Also, adopting energy efficiency strategies and renewable energy applications in buildings design generally and particularly in commercial buildings will drop the produced amount of CO₂ emissions, as well as operational emissions and embodied emissions are attributed to the building materials and energy required for construction.This research is proposing energy efficient commercial building design proposal as an approach to green architecture in Egypt. First, commercial buildings impact is studied, then choosing energy simulation tool to assess the solution as DesignBuilder software, the design of commercial building proposal respect the triple bottom line of sustainability, to introduce innovative, efficient and environmental building design respecting users’ needs and achieve high economic value, finally, after simulating the building model in DesignBuilder to reach the highest energy saving and ensure the thermal comfort for users, the design is evaluated by LEED criteria to measure the environmental impact of the building and indicate how this design is successful or not.Finally, this research focuses on proposing a design design cliteria and apply it on designing new commercial buildings to enhance the building performance and being environmentally integrated based on design design cliteria that represent the three major design principles and they are Nature, Culture and Art. Nature for respecting and integrating with the environment, Culture for respecting the location and user’s needs, Art for offering a unique architecture design leave strong mental image impression.

Abstract: A systematic experimental study is conducted on floating field rings (FFR) incorporated into 4H-SiC junction barrier Schottky (JBS) diodes across four voltage ratings 650, 1200, 1700 and 3300V, in pursuit of highly efficient FFR designs. 30 designs of FFR in 3 categories are studied for each voltage rating, and the measured breakdown voltage (Vbr) of JBS divided by ring system width (W) is taken as the figure of merit (FOM) of each design. The influence of ring spacing, ring width and number of rings on Vbr is studied in detail. It is found that the initial ring spacing (S1) is critical in determining the highest Vbr achievable by a certain design, and its optimum value increases as voltage rating increases. TCAD simulation verifies the importance of S1. For designs with a small ring system width, subsequent ring spacing can also become important. Ring width does not have a definitive effect, and Vbr saturates beyond a certain ring number. The design with the highest Vbr may not render the highest FOM. Even style designs with appropriate ring spacings can be advantageous likely due to less susceptibility to variation of field oxide charge, and more tolerance to fabrication error, as well as ease of design.