scholarly journals Design and Analysis of X Shaped Exhaust System Operation Using Different Types of Profiles on High Capacity Vehicle

2021 ◽  
pp. 19-27
Author(s):  
Menaka Muchhetti ◽  
Dharamkar Sai Suman ◽  
Boyanpally Abhiman ◽  
Samatham Madhukar
Keyword(s):  
Temperature Distribution ◽  
High Capacity ◽  
Exhaust System ◽  
Original Model ◽  
Exhaust Manifold ◽  
System Operation ◽  
Ic Engine ◽  
Flow Rates ◽  
Different Types ◽  
Engine System

The exhaust system used in a 4-stroke IC engine is mounted on the cylinder head of an engine. The gases exhausted from the engine recollected by the exhaust system and it is sent to a catalyst converter. The exhaust manifold has an important role in the performance of an engine system. The exhaust manifold affects the efficiencies of emission and fuel consumption. During the process of collecting the gas from engine and exhaust to catalyst converter, the exhaust manifold experiences temperatures of 800°c and the pressures varying from 100 to 500kpa. Here in this thesis we are going to choose a 4 cylinder 1500cc diesel engine of a car. In this paper, design of the original model and the modified models of X shaped systems using Catia software and then analysed using CFD software for the flow rates and the temperature distribution of the exhaust models. Finally better modification can be determined.

scholarly journals Design and Vibrational Characteristic Analysis of Exhaust Manifold with Experimental Validation Using FFT Analyzer

2021 ◽  
pp. 645-665
Author(s):  
Shubham Mittal ◽  
Dr. Kiran C. More
Keyword(s):  
Internal Combustion Engines ◽  
Experimental Validation ◽  
Exhaust System ◽  
Vertical Vibration ◽  
Combustion Engines ◽  
Exhaust Manifold ◽  
Characteristic Analysis ◽  
Vibrational Characteristic ◽  
Different Types ◽  
Vibration Problems

The vibrations observed in internal combustion engines transfer to the Tail pipe via exhaust manifold. Such Vibrations cause failure of exhaust system. Two types of vibration can affect the exhaust manifold: the sonic pressure waves coming from the exhaust ports, and the vibration of the engine itself. Pressure wave vibrations are usually transparent, travelling through the exhaust system to either absorb into or cancel out in the muffler. These waves are harmonic, like the vibration of a speaker, but they are usually too minute to cause noise through component movement. Engine vibrations, on the other hand, can easily shake your complete exhaust system. Such cyclic loading of waves can cause component rattling or failure. This vibration failure occurs due to resonant frequencies occurring in defined frequency range. The ‘frequency match’ could lead to a response detrimental to the life of the structure.FEA techniques are proposed in this work to avoid resonance. Physical experimentation is proposed using FFT Analyzer. This work deals with the damping of such later mentioned vibration problems with a concept of CAE (Computer Aided Engineering). In this project we are analyzing the exhaust system under various conditions for modal (natural vibrations). Static and modal analysis of exhaust manifold has been performed using ANSYS 19 software along with experimental validation of manifold using FFT and impact hammer test. Different types of methods for reducing vibration of manifold are studied. After studying these methods and procedures for reducing a vibration, we conclude that, exhaust manifold concept 02 is more efficient by changing the geometry or adding proper stiffener for reducing vertical vibration which further increases the frequency response of component..

The Reliability Improvement of a Conventional Cast Iron Exhaust Manifold for a Small Size Gasoline Engine

2004 ◽  
Author(s):  
Giuseppe De Angelis ◽  
Fernando Palomba
Keyword(s):  
Cast Iron ◽  
Temperature Distribution ◽  
Thermal Fatigue ◽  
Gasoline Engine ◽  
Exhaust System ◽  
High Temperature Phase ◽  
Exhaust Emission ◽  
Temperature Phase ◽  
Exhaust Manifold ◽  
Test Cycle

This paper describes a challenging phase of the development of a cast iron exhaust manifold for a FIAT FIRE 16v engine. On these engine family, a close-coupled catalyst directly connected to the manifold is used. Conventional cast iron could be considered an obsolete material to realize modern car engine exhaust manifolds, but it’s still considerable as a profitable technology due to relatively low processing and part costs. Moreover, due to actual exhaust emission regulation, the engine calibration determinates higher temperature values and gradients on the exhaust system than in the past. Consequently thermal fatique life, weight and manifold wall thickness limits become some of the main concerns for the engine designer when conventional cast iron is considered. To improve the actual cast iron manifold, according to the engine program timeline, a simplified, fast approach to thermal fatigue life improvement has been used, involving only in-house resources to achieve a further cost-time reduction in the definition and implementation of the necessary design changes. By means of Infrared Thermography, the distribution of the external surface of the exhaust manifold was acquired, on the engine bench, in-firing conditions, during specific accelerated thermal fatigue test cycle. The 2D surface temperature distribution was properly elaborated to obtain a 3D temperature distribution and a thermostructural FE Analysis has been developed to predict the critical areas of the component, considering the variation of the relevant material properties with temperature. The evaluation of the regions where thermal crack initiation and propagation were expected has been done considering the stress distributions in the high-temperature phase and during the cool-down phase of the test cycle. The comparison with the cracked manifold returned from the road test has shown a good agreement with the first results obtained from the analysis. For the optimisation, the same temperature acquisition and analysis were performed considering the manifold, made of the same material, used for a similar application for which no failures occurred during tests, obtaining information about the safe combination of stress and temperature level for the specific spheroid cast iron used. Those data were applied to validate the improved design that passed the following endurance tests, with only a minor acceptable impact in terms of weight, costs and development time.

scholarly journals Temperature log simulations in high-enthalpy boreholes

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Jia Wang ◽  
Fabian Nitschke ◽  
Maziar Gholami Korzani ◽  
Thomas Kohl
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Temperature Gradient ◽  
Flow Rate ◽  
Fluid Loss ◽  
Flow Conditions ◽  
Flow Rates ◽  
High Enthalpy ◽  
Fluid Losses ◽  
Lateral Heat

Abstract Temperature logs have important applications in the geothermal industry such as the estimation of the static formation temperature (SFT) and the characterization of fluid loss from a borehole. However, the temperature distribution of the wellbore relies on various factors such as wellbore flow conditions, fluid losses, well layout, heat transfer mechanics within the fluid as well as between the wellbore and the surrounding rock formation, etc. In this context, the numerical approach presented in this paper is applied to investigate the influencing parameters/uncertainties in the interpretation of borehole logging data. To this end, synthetic temperature logs representing different well operation conditions were numerically generated using our newly developed wellbore simulator. Our models account for several complex operation scenarios resulting from the requirements of high-enthalpy wells where different flow conditions, such as mud injection with- and without fluid loss and shut-in, occur in the drill string and the annulus. The simulation results reveal that free convective heat transfer plays an important role in the earlier evolution of the shut-in-time temperature; high accuracy SFT estimation is only possible when long-term shut-in measurements are used. Two other simulation scenarios for a well under injection conditions show that applying simple temperature correction methods on the non-shut-in temperature data could lead to large errors for SFT estimation even at very low injection flow rates. Furthermore, the magnitude of the temperature gradient increase depends on the flow rate, the percentage of fluid loss and the lateral heat transfer between the fluid and the rock formation. As indicated by this study, under low fluid losses (< 30%) or relatively higher flow rates (> 20 L/s), the impact of flow rate and the lateral heat transfer on the temperature gradient increase can be ignored. These results provide insights on the key factors influencing the well temperature distribution, which are important for the choice of the drilling data to estimate SFT and the design of the inverse modeling scheme in future studies to determine an accurate SFT profile for the high-enthalpy geothermal environment.

Satellite Channels Based on IEEE 802.16 Standard

2019 ◽  
pp. 133-166
Keyword(s):  
Frequency Shift ◽  
Communication Channels ◽  
Ieee 802.16 ◽  
Original Model ◽  
Doppler Shifts ◽  
Time Diversity ◽  
Different Types ◽  
Satellite Channels ◽  
The Impact ◽  
Aircraft Data

This chapter considers the modeling of RPAS/Aircraft data transmission via channels based on IEEE 802.16 standard. RPAS communication channel with a fading was analyzed using original model. Dependencies of a SNR in ground receiver on a SNR in downlink for different types of RPAS amplifier nonlinearity were obtained. Signals constellations of received signals were compared for different Doppler shifts. The influence of the aircraft transmitter nonlinearity for different types of fading in the channel was studied using “80216dstbc Rayleigh,” “80216dstbc Rician,” “80216d Rayleigh,” and “80216d Rician” models. The possibility of the nonlinearity correction using pre-distortion was revealed. The impact of space-time diversity (MISO 2x1) for different types of fading in the channels was investigated. The effect of the Doppler's frequency shift on the operation of communication channels was analyzed.

Use of Early Exhaust Valve Opening to Improve Combustion Efficiency and Catalyst Effectiveness in a Multi-Cylinder RCCI Engine System: A Simulation Study

2014 ◽  
Author(s):  
Anand Nageswaran Bharath ◽  
Nitya Kalva ◽  
Rolf D. Reitz ◽  
Christopher J. Rutland
Keyword(s):  
System Simulation ◽  
Combustion Efficiency ◽  
Exhaust Valve ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Flow Rates ◽  
Low Load ◽  
Valve Opening ◽  
Engine System ◽  
Exhaust Gas Temperature

Low Temperature Combustion (LTC) strategies such as Reactivity Controlled Compression Ignition (RCCI) can result in significant improvements of fuel economy and emissions reduction. However, they can produce significant carbon monoxide and unburnt hydrocarbon emissions at low load operating conditions due to poor combustion efficiencies at these operating points, which is a consequence of the low combustion temperatures that cause the oxidation rates of these species to slow down. The exhaust gas temperature is also not high enough at low loads for effective performance of turbocharger systems and diesel oxidation catalysts (DOC). The DOC is extremely sensitive to exhaust gas temperature changes and lights off only when a certain temperature is reached, depending on the catalyst specifications. Uncooled EGR can increase combustion temperatures, thereby improving combustion efficiency, but high EGR concentrations of 50% or more are required, thereby increasing pumping work and reducing volumetric efficiency. However, with early exhaust valve opening, the exhaust gas temperature can be much higher, allowing lower EGR flow rates, and enabling activation of the DOC for more effective oxidization of unburnt hydrocarbons and CO in the exhaust. In this paper, a multi-cylinder engine system simulation of RCCI at low load operation with early exhaust valve opening is presented, along with consideration of the exhaust aftertreatment system. The combustion process is modeled using the 3D CFD code, KIVA, and the heat release rates obtained from this combustion are used in a GT-Power model of a turbocharged, multi-cylinder light-duty RCCI engine for a full system simulation. The post-turbine exhaust gas is fed into GT-Power’s aftertreatment model of the engine’s DOC to determine the catalyst response. It is confirmed that opening the exhaust valve earlier increases the exhaust gas temperature, and hence lower EGR flow rates are needed to improve combustion efficiency. It was also found that exhaust temperatures of around 457 K are required to light off the catalyst and oxidize the unburnt hydrocarbons and CO effectively. Performance of the DOC was drastically improved and higher amounts of unburnt hydrocarbons were oxidized by increasing the exhaust gas temperature.

Enhancement of the Completion Efficiency of Perforation Tunnels in Petroleum Wells

2006 ◽  
Author(s):  
M. A. Rahman ◽  
T. Heidrick ◽  
B. Fleck ◽  
M. Koksal
Keyword(s):  
Fluid Flow ◽  
Conventional Method ◽  
Differential Pressure ◽  
Triaxial Testing ◽  
Flow Rates ◽  
Different Types ◽  
Set Up ◽  
Petroleum Wells ◽  
Perforated Completion ◽  
The Ideal

The objective of perforating is to maximize well productivity by establishing good connectivity between the wellbore and formation. The conventional method of perforation — perforation by shooting (PS) — cannot achieve expected wellbore productivity due to a region of reduced permeability around the perforation tunnel. In this study, it has been established that permeability is decreased in the range of 30%–75% due to the implementation of the PS technique compared to the openhole completion. As a result, a new perforation technique — perforation by drilling (PD) — has been proposed in this paper. To simulate a perforated completion, cylindrical sand samples (0.0572 in OD) consolidated with cement with varying porosity were prepared. These samples were perforated (0.0136 m ED) by the PS, PD and Casting techniques. Perforations created by the Casting techniques are considered the ideal, openhole perforation tunnel. Fluid flow rates and differential pressure across the perforated samples were measured for three different types of samples using “Geotechnical Digital System” triaxial testing set-up. Fluid flow rates with changing differential pressure and finally pressure build-up data with time indicates the PD technique can achieve better wellbore productivity compared to the PS technique. Results indicate that at 100 kPa differential pressure the PS, PD and Casting techniques can achieve 0.20 mL/s, 0.65 mL/s and 1.00 mL/s fluid flow rates respectively across a sample.

scholarly journals Finite element analysis of heat sink in term of thermal and temperature distribution with different chip power input

2018 ◽  
Vol 7 (2.15) ◽  
pp. 90
Author(s):  
Mazlan Mohamed ◽  
Mohd Nazri Omar ◽  
Mohamad Shaiful Ashrul Ishak ◽  
Rozyanty Rahman ◽  
Muhamad Fahmi Mohd Roslan ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Heat Sink ◽  
3D Model ◽  
Power Input ◽  
Power Source ◽  
Experimental Setup ◽  
Time Step ◽  
Element Analysis ◽  
Different Types ◽  
Lower Temperature

This paper presents the simulation of heat sink by using Workbench 18.0 Software to simulate the temperature distribution at different chip power input. 3D model of heat sink is generated using Design Modeler using the same dimension with experimental setup. The study was made for a heat sink mounted on the power source (Chip) under different types of chip powers. The results are presented in terms of temperature distribution when chip powers have been increased from 1 W to 10 W. The temperature distribution is been observed and it was found that the temperature distribution of the heat sink has lower temperature when power source at 1 W and increase significantly when the power source rise up to 10 W. The increase the temperature of heat sink is from 30.8ºC up to 96.2ºC estimated to be 212% the increase of temperature. The simulation also been verify by using different time step use during the simulation and using grid independency test to ensure the simulation result is accurate. 

Spreadsheet as a Data Acquisition Tool in Turbomachinery

2010 ◽  
Author(s):  
Abraham Engeda
Keyword(s):  
Data Acquisition ◽  
Rotating Stall ◽  
Relative Speed ◽  
Vaneless Diffuser ◽  
Flow Rates ◽  
One Dimensional ◽  
Measurement And Analysis ◽  
Different Types ◽  
Unsteady Characteristics ◽  
The One

This paper shows the power of spreadsheets as a strong tool in engineering teaching and research labs. In applied thermo-fluid education, even the one dimensional design or simple experimental measurement and analysis becomes a very complex exercise unless the procedure is programmed. Due to lengthy calculations and iterations, simple solutions are not possible. Exercises have therefore been limited in the classroom. But recent advances in powerful spreadsheets have opened a simple and fast way of performing design and advanced measurements. In recent times due to the introduction of a variety of mathematical soft wares, students have been relived from unnecessary time consuming chores; and therefore, complex measurements can now be carried out more comprehensively and easily. This paper reports on an experimental investigation to determine the effect of the vaneless diffuser width on the unsteady flow performance of a centrifugal compressor stage, where the whole data processing was carried out using a spreadsheet both for the steady and unsteady characteristics. Two compressor configurations with different vaneless diffuser width were investigated at four different impeller speeds and compared in the frequency and time domain. Only one diffuser rotating stall but different types of impeller rotating stalls were detected. The experiments show that the diffuser has a strong influence on the flow in the impeller including in areas way upstream. Analysis of the results indicated: • With increasing diffuser width the onset of impeller rotating stall was shifted to lower flow rates. • With increasing diffuser width the frequencies of the rotating stalls decreased. • There is a common tendency in most of the experiments to lower numbers of rotating cells with increasing relative speed. The whole data acquisition, processing and presentation are carried out using Excel.

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