Optimizing piston velocity profile for maximum work output from a generalized radiative law Diesel engine
نویسندگان
چکیده
ADiesel cycle enginewith internal and external irreversibilities of finite combustion rate of the fuel, friction and heat leakage is investigated in this paper. The heat transfer between the working fluid and the environment outside the cylinder obeys generalized radiative heat transfer law [q ∝ ∆(T n)]. Under the conditions of the fixed total cycle time and fuel consumed per cycle, the optimal piston motion trajectories for maximizing the work output per cycle of the cases with unconstrained and constrained piston accelerations are derived on each stroke by applying optimal control theory. The optimal distribution of the total cycle time among the strokes is also obtained. The optimal piston motion along the power stroke with constrained acceleration consists of three segments including the initial motion delay, themiddlemotion and the finalmaximumdeceleration segments. Numerical examples for the case with the radiative heat transfer law [q ∝ ∆(T 4)] and constrained acceleration are provided, and the obtained results are also compared with those obtained with Newtonian [q ∝ ∆(T )] and linear phenomenological [q ∝ ∆(T−1)] heat transfer laws. The results show that optimizing the piston motion for the case with the radiative heat transfer law can improve both the net work output per cycle and the net efficiency of the standard engine bymore than 7%, and heat transfer laws have significant effects on the optimal piston motion trajectory for maximum work output. © 2011 Elsevier Ltd. All rights reserved.
منابع مشابه
OPTIMAL PATHS OF PISTON MOTION OF IRREVERSIBLE DIESEL CYCLE FOR MINIMUM ENTROPY GENERATION By
A Diesel cycle heat engine with internal and external irreversibilities of heat transfer and friction, in which the finite rate of combustion is considered and the heat transfer between the working fluid and the environment obeys Newton’s heat transfer law [ ( ) q T ≈ ∆ ], is studied in this paper. Optimal piston motion trajectories for minimizing entropy generation per cycle are derived for th...
متن کاملInvestigation of the effect of piston geometrical parameters on RCCI engine performance based on second law of thermodynamic
The reactivity controlled compression ignition engines have high thermal efficiency and low exhaust emission of nitrogen oxides and soot because of low temperature combustion. In this type of engines, low reactivity fuel is injected to air through intake port and high reactivity fuel is injected into the combustion chamber during compression stroke. The aim of current study is to investigate th...
متن کاملEvaluating the Effects of Ceramic Layer and Thermal Dam on Optimizing the Temperature Gradient of a Gasoline Engine Piston (TECHNICAL NOTE)
The purpose of this paper is to evaluate the effect of different methods for improving the temperature gradient of a specified gasoline engine piston. With a robust FE based software, 3D thermal analyses have been carried out for the piston model. Unlike previous studies, the effects of both fully and locally ceramic layers on the crown top surface were considered. It was found that a fully cer...
متن کاملExperimental Investigation of the Effects of Air Injectionand Injection Timingin a Natural Aspirated DI Diesel Engine
In this experimental study, the effect of creating an air jet inside the combustion chamber by establishing an air-cell inside of the piston body at different injection timings in a DI diesel engine has been studied at 2000 rpm and full load operation. The performed tests include studying the Soot and NOx emissions, combustion and performance parameters. The obtained experimental results show t...
متن کاملEngine characterization study of hydrocarbon fuel derived through recycling of waste transformer oil
This work intends to capitalize waste transformer oil (WTO) as a renewable source of fuel in a diesel engine, given the cost of fuel being used is reduced when using waste products. Previously, despite its higher viscosity, WTO is used as such or in blends with diesel in a diesel engine. However, in the current study, efforts are taken to chemically treat WTO so as to bring down its viscosity a...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Mathematical and Computer Modelling
دوره 54 شماره
صفحات -
تاریخ انتشار 2011