International Journal of Advanced Design and Manufacturing Technology: 4 (1)

Open Access Article

1 - Exergy Analysis for Heat Pipe over a Permeable Vertical Thin Cylinder In a Porous Medium
Mehdi Asghari Cirus Aghanajafi

Today heat pipes are widely used by the designers in industries such as air conditioning and heat transformers for optimizing energy consumption. Existence of a permeable cylinder at the beginning and ending part of the heat pipe was considered on the basis of two assum More

Today heat pipes are widely used by the designers in industries such as air conditioning and heat transformers for optimizing energy consumption. Existence of a permeable cylinder at the beginning and ending part of the heat pipe was considered on the basis of two assumptions for surface temperature of the cylinder and the mainstream velocity at the outer edge of the boundary layer vary linearly with the axial distance x from the leading edge. In this paper solution has been presented analytically with introduction of mixed convection parameter and coefficient of porosity . Various forms of flow were examined and the optimum state for minimum entropy generation was suggested. Manuscript profile

Open Access Article

2 - Mechanical Properties of Basalt/Epoxy Composites
Mahmoud Mehrdadshokriyeh Mehdi Memar

The purpose of this paper is to determine mechanical properties of Basalt/Epoxy composites. Test samples were unidirectional composite samples which they are tested according to ASTM D790-96 standard test method by a universal testing machine. Ultimate strength, modulus More

The purpose of this paper is to determine mechanical properties of Basalt/Epoxy composites. Test samples were unidirectional composite samples which they are tested according to ASTM D790-96 standard test method by a universal testing machine. Ultimate strength, modulus of elasticity and fracture energy of bending samples are gained. Then pay attention to conditions of unidirectional samples and doing tensile tests on samples, transition coefficients to transfer bending properties to tensile and compressive properties are gained. Using bending test results tensile and compressive properties of samples consist of strength and modulus of elasticity are derived. Manuscript profile

Open Access Article

3 - An Investigation of Lid Driven Cavity Flow Using Large Eddy Simulation
Iman Nourollahi

In this paper we use of large eddy simulation method for 2 dimensional incompressible fluid in square lid-driven cavity. We also apply smagorinsky SGS model for attach sub grid scales. In order to we have written a computer program with finite volume method and implicit More

In this paper we use of large eddy simulation method for 2 dimensional incompressible fluid in square lid-driven cavity. We also apply smagorinsky SGS model for attach sub grid scales. In order to we have written a computer program with finite volume method and implicit for discretization unsteady governing equations and we use of simple algorithm for pressure term. Our computation get from Re=100 up to Re=10000 and we obtain mean horizontal velocity, mean vertical velocity in central line, stream line and pressure contour and also we have calculated fluctuation of velocities and in finally we accepted Reynolds stress in Re=10000. The results are in good agreement with the experimental and numerical data. Manuscript profile

Open Access Article

4 - Analytical and Simulation of Free-Free Beam Subjected to Concentrated Impact Loadings
Reza Mohamadipour Ebrahim Harirbafan Mohsen Mohseni

Impact loading of free-free beam is of high interest to researchers as well as industry application. In this article a free-free beam subjected to concentrated impact loading is considered. Beam material is considered to be a rigid perfect plastic. Different combination More

Impact loading of free-free beam is of high interest to researchers as well as industry application. In this article a free-free beam subjected to concentrated impact loading is considered. Beam material is considered to be a rigid perfect plastic. Different combinations of loads, energy absorption and load location are considered. The result of the analysis show that when the load is less than critical load, the beam acts as a rigid body and when the load is greater than critical load three different mechanisms prevail. The result of the experiment is compared with analytical as well as simulation process using ABAQUS. The results of the compression are in good agreement with experimental investigation. Manuscript profile

Open Access Article

5 - Dynamic Design Principles of a Thrust Stand and Methods of Improving Frequency Response
Mojtaba Heydari Amir Alaedin Motallebi Sadegh Rahmati Ebrahim Harirbafan

Successful development, evaluation, and qualification of propulsion systems such as turbojet and turbofan engines and rocket motors require the measurement of the performance and reliability of these systems. Thrust stands or testers are instruments for solid and liquid More

Successful development, evaluation, and qualification of propulsion systems such as turbojet and turbofan engines and rocket motors require the measurement of the performance and reliability of these systems. Thrust stands or testers are instruments for solid and liquid motors test. These apparatuses extract the characteristics of motors such as temperature, pressure, force and torque. In this paper, the dynamic design principles of a typical thrust stand have been detailed and methods to improve dynamic response have been developed. A thrust stand should be affected by random vibrations of solid motors as slightly as possible during firing. At first some Power Spectral Density (PSD) of three kinds of solid motors has been calculated by MATLAB codes. Then a number of tester structures by Solidworks have been designed and their dynamic responses have been determined by ANSYS codes. An attempt has been made to improve dynamic responses through changing the structure. Results showed that just some models could be improved. Increase of natural frequencies protects the structure from motors random vibrations. Truss structure is a good choice for testers. Decrease of mass, using different types of tube sections and short members are effective methods for improving dynamic responses. Manuscript profile

Open Access Article

6 - Mold Less Casting, a New Method for Droplet Based Part Manufacturing
Mehrdad Vahdati Hamed Kalami

In the new method of rapid manufacturing, the molten metal is dropped on a substrate, making layers after another. This method has the potentiality to be used for complicated castings which are difficult to make their molds and patterns as usual ways. In droplet-based m More

In the new method of rapid manufacturing, the molten metal is dropped on a substrate, making layers after another. This method has the potentiality to be used for complicated castings which are difficult to make their molds and patterns as usual ways. In droplet-based manufacturing process the castings are constructed by molten metal droplets having proper flow rate, temperature and diameter. In this paper a new system is designed and constructed which makes 3D parts and patterns by depositing molten metal droplets. Raw material wire melts and droplets are generated in droplet generating head. Molten metal Droplets deposit on a high temperature bed making the first layer. Next layers place on the previous ones to shape the final arbitrary part. These droplets are surrounded by natural air. Here tin60%, lead40% alloy wire is used. it is possible to apply other materials or wires having different diameters just with a little change in system. The wire is fed in special speeds which lead to different rates of droplets leaving the nozzle. Droplets have three properties which affect the layers and depositing way. These properties are droplet temperature and volume and their deposition rate. To control them several parameters of the system must be adjusted appropriately. At first it is assumed that these machine parameters are outlet nozzle diameter and feeding wire speed and also droplet temperature which affect droplet volume and deposition rate. Droplet temperature is measured exactly where they leave outlet nozzle. Droplet volume is estimated by several experiments, which lead to learn how different machine parameters create various droplet volumes. By knowing droplet volume and feeding wire speed, droplet rate can be calculated.In this paper the design essence of the constructed droplet based manufacturing machine is told. And dependency of droplet properties to machine adjustments is studied. These studies are done to control droplet properties. By knowing droplet properties, the moving speed of CNC heating table is determined. Manuscript profile

Open Access Article

7 - Investigation on Microstructure and Production of Coaxial Cable Foam Insulation using Butane Gas
Mehdi Nazri AmirHosein Behravesh Payman Shahi

This paper presents an investigation on the effect of temperature and raw material on microstructure of fine cellular foam used as the insulation of coaxial cables. A set up was prepared and used to produce fine cellular foamed insulation. As the physical blowing agent, More

This paper presents an investigation on the effect of temperature and raw material on microstructure of fine cellular foam used as the insulation of coaxial cables. A set up was prepared and used to produce fine cellular foamed insulation. As the physical blowing agent, butane was used. The effect of temperature on the microstructure of polyethylene (PE) was worth to note. At high temperature, due to low melt strength, large cells with low cell density was observed. As the temperature was decreased, the number of nucleated cells was increased and also a decrese in cell size was observed. Too law a temperature, caused a decrese in number of nucleated cells. To investigate the effect of raw material on microstructure, a blend of polyethylene (LDPE-HDPE) was used. This blend, via increasing the melt strength, led to a microstructure with150 micron cell size. Finally, the attenuation property of the produced cable with optimum microstructure was compared with a same cable produced with chemical foam insulation. The results showed 17% reduction in attenuation property of the coaxial cable with physical foam insulation. Manuscript profile

Open Access Article

8 - Aerodynamic Parameter Corrections for Surface to Air Missiles Using Tail Flap Vibration Feedback
AhmadReza Khougar Mohsen Azadeh

The Transfer functions of missiles change during flight. For proper control and desired performance of missiles through different situations during flight, their aerodynamic derivatives and mass inertia parameters need to be corrected at different working points. In thi More

The Transfer functions of missiles change during flight. For proper control and desired performance of missiles through different situations during flight, their aerodynamic derivatives and mass inertia parameters need to be corrected at different working points. In this paper the feedback of the tail flap vibrations are used to specify the gains and the aerodynamic parameters of a surface to air missile, for use in the transfer functions. The vibration characteristics of the tail flaps are usually good index of the missile’s speed and consequently its dynamic pressure which, can be used for aerodynamics and gain correction in different working points in the transfer functions. The vibration feedback from the tail flaps were used in a six degree of freedom missile simulation integrated with the tail flaps vibration model and the IMU model. Simulation results and its comparison with recorded results from test flights, shows that the vibration feedback from the tail flaps can quite adequately be used for estimation of missile speed, dynamic pressure, and correction of aerodynamic parameters of the transfer functions. Manuscript profile

XML

List of Articles