Showing 5 results for Turbocharger
J. Mahdavinia, A. Keshavarz, M.h. Moshrefi,
Volume 1, Issue 1 (1-2011)
Abstract
Turbocharging an engine boosts its power by increasing the amount of input air. This task is accomplished by using the exhaust gas to power a turbine which is engaged with a compressor. The Variable Geometry Turbocharger, VGT is a unique turbocharger that the diffuser vane angle can be changed over a wide range of positions. The mathematics of turbomachinery flow analysis is intensive and uses iterative methods. Most of the flow analyses in the area of turbochargers are either experimental or numerical. Three-dimensional Computational Fluid Dynamics (CFD), two-dimensional multiple streamline and one dimensional mean line is the three primary numerically available methods. In this paper a mean line method has been used for predicting the performance of a centrifugal compressor with variable diffuser vane angle position at subcritical Mach numbers. The calculation is based on common thermodynamic and aerodynamic principles, and empirical correlations for losses in a mean line analyses. The model calculates the velocities, pressures, temperatures, pressure losses, work consumption, and efficiencies for a specified set of turbocharger geometry, atmospheric conditions, rotational speed, and fluid mass flow rate. The obtained numerical results are validated with the in house measured experimental data and good agreement observed. The purpose for compressor model analysis is to generate overall characteristic map and identify the impact of the diffuser vane angles on the performance. The overall characteristic map is generated by this method demonstrate very good agreement and the effect of variable vane angle in pressure ratio and operating range observed.
E. Safarian, K. Bilen, M. Akif Ceviz , A. Salimias,
Volume 6, Issue 3 (9-2016)
Abstract
The usage of turbochargers in diesel engines has led to the downsizing of the motors as well as usage of the waste gates in turbochargers. Any dimensional reduction in turbochargers and appurtenant leads to an enhancement on the performance of internal combustion engines and in environmental problems in terms of aerodynamic, thermodynamic and mechanical specifications for both engines and turbochargers. For this reason, the efforts need to be focused on the design of turbochargers and their waste gates accurately, in order to maintain its benefits as much as possible. The extent of waste gate opening, from full opened to closed valve, is demonstrated by the limiting compressor boost pressure ratio. Ultimately, an optimum point of limiting compressor boost pressure ratio is obtained then an increase in the values of BMEP and engine power for the same fuel consumption in range of waste gate opening is achieved
S. Shavvalpoour, M. Nikravan,
Volume 7, Issue 2 (6-2017)
Abstract
Recent evolutions in World Trade Organization (WTO) and other international trading agreements have made industries all around the world face a new era of intense global competition. Simultaneously with increased competitive pressure, permanent development and innovation comprise building blocks of firm excellence. In a dynamic environment, failure to innovate ends up with business stagnation and getting out of the competition ring.
Technological innovation capability is a complex, elusive and uncertain concept, which have made it difficult to characterize. Measuring technological innovation capability requires considering numerous qualitative and quantitative criteria at the same time. One of the main factors hindering the success of adopting technological innovation to attain competitive advantage by firms in developing countries is lack of awareness about and recognition of the level of firm technological capabilities and how to use them to acquire relative advantages. Evaluation of technological capability serves as a tool for identifying the required capabilities to implement the firm technological priorities.
Based on a wide spectrum of available literature, the present paper attempts to extract criteria related to technological innovation capabilities in the field of turbocharging technology. These criteria were then provided to a group of experts in automotive industry, so as to identify the desired level of technology for turbocharging technology in automotive industry. On the other hand, by restricting items of the questionnaire based on the experts’ opinions, the current state of turbocharging technology capabilities was identified, based on which technological gap in each criterion under study was determined. On the other hand, once the technological gap was identified, improvement projects were defined to either suppress or eliminate the gap.
Dr Javad Zareei, Prof Mohamad Hasn Aghakhani, Mr Saeed Ahmadipour,
Volume 9, Issue 3 (9-2019)
Abstract
Changing the compression ratio and presence of turbocharger are two important issues, affecting on performance, and exhaust emissions in internal combustion engines. To study the functional properties and exhaust emissions in regards to compression ratio at different speeds, the numerical solution of the governing equations on the fluid flow inside the combustion chamber and the numerical solution of one-dimensional computational fluid dynamics with the GT-Power software carried out. The diesel engine was with a displacement of 6.4 Lit and Turbocharged six-cylinder. In this engine was chosen, the compression ratio between 15: 1 and 19: 1 with intervals of one unit and the range of engine speed was from 800 to 2400 rpm. The results showed that by the presence of a turbocharger and changing the compression ratio from 17: 1 to 19: 1, the braking power and torque increased by about 56.24% compared to the non-turbocharged engine. In addition, was reduced the brake specific fuel consumption due to higher power output. The amount of CO and HC emissions decreases based on the reduction of the compression ratio compared to the based case, and the NOX value increases due to the production of higher heat than turbocharged engines. The overall results showed that the turbocharged engine with a 19: 1 compression ratio has the best performance and pollution characteristics.
Javad Zareei, Saeed Ahmadi,
Volume 10, Issue 3 (9-2020)
Abstract
In internal combustion engines, the turbocharger and alternative fuels are two important factors affecting engine performance and exhaust emission. In this investigation, a one-dimensional computational fluid dynamics with GT-Power software was used to simulate a six-cylinder turbocharged diesel engine and the naturally aspirated diesel engine to study the performance and exhaust emissions with alternative fuels. The base fuel (diesel), methanol, ethanol, the blend of diesel and ethanol, biodiesel and decane was used. The results showed that decane fuel in the turbocharged engine has more brake power and torque (about 3.86%) compared to the base fuel. Also, the results showed that the turbocharger reduces carbon monoxide and hydrocarbon emissions, and biodiesel fuel has the least amount of carbon monoxide and hydrocarbon among other fuels. At the same time, the lowest NO
X emission was obtained by decane fuel. As a final result can be demonstrated that the decane fuel in the turbocharged engine and the biodiesel fuel in the naturally aspirated engine could be a good alternative ratio to diesel fuel in diesel engines.
