scholarly journals Design and Analysis of Exhaust Manifold

Author(s):  
Anand D ◽  
Suresh Vellingiri

The exhaust manifold system is mountedon the cylinder head of theengine. It is associated with the catalyst converter at the other end. The emitted gases transmitted from the chamber come out at temperatures of about 800 °C and with pressures extending from 100 to 500 kPa. The exhaust manifold system is exposed to high temperatures and weights which will lead to thermo mechanical failure. Redesigning an exhaust manifold by determining Thermal stresses and deflections exhibited under various operating conditions with different materials and temperatures. The objective is to ensure the suitability of the design for a particular material from the view point of reliability and serviceability.  Defects in existing manifold are cracks usually occur due to prolonged exposure to extreme temperatures, defects in casting and Heat cycling. High end cad cam software such as Unigraphics and Ansys is used for modeling and analysis. The 3d Model of exhaust manifold is subjected to thermal and structural loads and results are tabulated according to the procedure for the Exhaust manifold.

2013 ◽  
Vol 631-632 ◽  
pp. 1335-1341
Author(s):  
Shi Yong ◽  
Wen Tao Liu

In order to meet the needs of enterprises for chamfering complex parts, based on the customization of commercial CAD/CAM software, chamfer programming software is developed. According to user’s machining demands for a part, a chain of edges of a part is extracted from its 3D model. With preprocessing of the chain of edges, the continuity of the chain is estimated, and the start and end point of those edges are automatic obtained. Furthermore, with human-machine dialogue, machining parameters is set by users. By definition of the primary and secondary surfaces of the chain of edges, and interpolation of the edges, the positions of cutter location point and postures of cutter are calculated. Finally the interference of tool path is checked, and tool path is simulated. The software solves the programming problem of chamfering complex parts.


In the past three decades, it is very challenging for the researchers to design and development a best gas turbine engine component. Engine component has to face different operating conditions at different working environments. Nickel based superalloys are the best material to design turbine components. Inconel 718, Inconel 617, Hastelloy, Monel and Udimet are the common material used for turbine components. Directional solidification is one of the conventional casting routes followed to develop turbine blades. It is also reported that the raw materials are heat treated / age hardened to enrich the desired properties of the material implementation. Accordingly they are highly susceptible to mechanical and thermal stresses while operating. The hot section of the turbine components will experience repeated thermal stress. The halides in the combination of sulfur, chlorides and vanadate are deposited as molten salt on the surface of the turbine blade. On prolonged exposure the surface of the turbine blade starts to peel as an oxide scale. Microscopic images are the supportive results to compare the surface morphology after complete oxidation / corrosion studies. The spectroscopic results are useful to identify the elemental analysis over oxides formed. The predominant oxides observed are NiO, Cr2O3, Fe2O3 and NiCr2O4. These oxides are vulnerable on prolonged exposure and according to PB ratio the passivation are very less. In recent research, the invention on nickel based superalloys turbine blades produced through other advanced manufacturing process is also compared. A summary was made through comparing the conventional material and advanced materials performance of turbine blade material for high temperature performance.


2013 ◽  
Vol 702 ◽  
pp. 259-262 ◽  
Author(s):  
Cezary Grabowik ◽  
Witold Janik

Currently industrial needs exceed traditional design approach solutions. To satisfy that need designer have to deal with mutually exclusive restrictions. The solution to this problemis to maintain these restrictions with proper methodthat guarantees right result. The concrete casting matrixes are not only transits beauty and art but they have also important technical sense in final product. The master model represents the final product a concrete sidewalk brick which have specified form of the top surface. This special structure of the top surface helps drain water off the brick in order to maintain proper griping properties of it after it rains. As soon as the master model wasscannedit was necessary to change outer border line of 3D model because themaster model appeared to be a little bit bigger than the original one. Finally the 3D model it is the outer border line and its geometry were modified in order to keep the original model functionality. All modifications were done with application of reverse engineering and CAD/CAM software.


2012 ◽  
Vol 591-593 ◽  
pp. 77-79
Author(s):  
Ai Hua Chen ◽  
Ming Xia ◽  
Yong Hui Tang ◽  
Ying Zhang

With the help of IGES standard file which was the exchange specification of initial graphics, different CAD system could change the data of product by neutral file’s format conversing. The automatic generation of 3D-Model curve surface in the MCNP input file was realized by using VC++ language.This method has solved the problem of the complication of MCNP geometric modeling process and the 3D-Model input problem in the MCNP. The input of MCNP was transferred the application problem of CAD/CAM software. The data and figure of varies software could be shared and converted. The work of design could be simple, the process of design could be speeded up and the cycle of design was shorted. Work efficiency and practicability were improved. If precision was controlled in 3D-Model, the result could be expected by contrast.


Author(s):  
Z. F. Z. Abidin ◽  
M. N. Osman Zahid

Object customization in Computer Aided Design (CAD) is a method used to modify the sketch parameters and change the model geometries. This method is one of important features in part modelling which empowered CAD user to simply modify their product. The conventional method of modifying CAD model is usually relied on the manual editing. This paper outlines a development of program than can be integrated in CAD/CAM system for real time object customization. It uses Visual Basic (VB) programming with custom Graphical User Interface (GUI) generated in NX10 (CAD/CAM software) interface. The main contribution of this research is a tool for real time object customization that capable to assist the modification of 3D model. In order to develop the tool, 3D model modification instructions are translated into programming codes by using Journaling tools in NX interface. Editable parameters are identified based on the model shapes. The related codes are reconstructed, modified and linked to the functional GUI.  This allows user to simply modify the model shapes in real time with minimum process steps. The performance of the method is evaluated in terms of the reduction of process steps and time in modifying the 3D model in CAD system. All the findings and details of approach are presented.


1996 ◽  
Vol 118 (1) ◽  
pp. 164-172 ◽  
Author(s):  
C. H. Amon ◽  
K. S. Schmaltz ◽  
R. Merz ◽  
F. B. Prinz

A molten metal droplet landing and bonding to a solid substrate is investigated with combined analytical, numerical, and experimental techniques. This research supports a novel, thermal spray shape deposition process, referred to as microcasting, capable of rapidly manufacturing near netshape, steel objects. Metallurgical bonding between the impacting droplet and the previous deposition layer improves the strength and material property continuity between the layers, producing high-quality metal objects. A thorough understanding of the interface heat transfer process is needed to optimize the microcast object properties by minimizing the impacting droplet temperature necessary for superficial substrate remelting, while controlling substrate and deposit material cooling rates, remelt depths, and residual thermal stresses. A mixed Lagrangian–Eulerian numerical model is developed to calculate substrate remelting and temperature histories for investigating the required deposition temperatures and the effect of operating conditions on remelting. Experimental and analytical approaches are used to determine initial conditions for the numerical simulations, to verify the numerical accuracy, and to identify the resultant microstructures. Numerical results indicate that droplet to substrate conduction is the dominant heat transfer mode during remelting and solidification. Furthermore, a highly time-dependent heat transfer coefficient at the droplet/substrate interface necessitates a combined numerical model of the droplet and substrate for accurate predictions of the substrate remelting. The remelting depth and cooling rate numerical results are also verified by optical metallography, and compare well with both the analytical solution for the initial deposition period and the temperature measurements during droplet solidification.


2005 ◽  
Vol 277-279 ◽  
pp. 318-323
Author(s):  
Yang Hee Nam

Architectural design is one of those areas that have actively employed interactive design tools such as CAD/CAM software. In order to add a realistic view of the design results in the 3D work process, there have been several recent attempts to employ a virtual reality technology that allows architects to explore design in 3D space. However, VR’s weakness is that common interaction tasks, such as navigation and selection, are still not supported conveniently in 3D space. In addition, VR devices are generally unfamiliar to the average person and are too expensive to use. This paper presents a VR framework that makes the design task easily achieved by employing a PDA interface for a VR interaction applied to street-view emotional color design problems.


2021 ◽  
Author(s):  
Eva Alvarez-Regueiro ◽  
Esperanza Barrera-Medrano ◽  
Ricardo Martinez-Botas ◽  
Srithar Rajoo

Abstract This paper presents a CFD-based numerical analysis on the potential benefits of non-radial blading turbine for low speed-low pressure applications. Electric turbocompounding is a waste heat recovery technology consisting of a turbine coupled to a generator that transforms the energy left over in the engine exhaust gases, which is typically found at low pressure, into electricity. Turbines designed to operate at low specific speed are ideal for these applications since the peak efficiency occurs at lower pressure ratios than conventional high speed turbines. The baseline design consisted of a vaneless radial fibre turbine, operating at 1.2 pressure ratio and 28,000rpm. Experimental low temperature tests were carried out with the baseline radial blading turbine at nominal, lower and higher pressure ratio operating conditions to validate numerical simulations. The baseline turbine incidence angle effect was studied and positive inlet blade angle impact was assessed in the current paper. Four different turbine rotor designs of 20, 30, 40 and 50° of positive inlet blade angle are presented, with the aim to reduce the losses associated to positive incidence, specially at midspan. The volute domain was included in all CFD calculations to take into account the volute-rotor interactions. The results obtained from numerical simulations of the modified designs were compared with those from the baseline turbine rotor at design and off-design conditions. Total-to-static efficiency improved in all the non-radial blading designs at all operating points considered, by maximum of 1.5% at design conditions and 5% at off-design conditions, particularly at low pressure ratio. As non-radial fibre blading may be susceptible to high centrifugal and thermal stresses, a structural analysis was performed to assess the feasibility of each design. Most of non-radial blading designs showed acceptable levels of stress and deformation.


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