Rate of Heat Release in High-Speed Indirect Injection Diesel Engines

1969 ◽  
Vol 184 (10) ◽  
pp. 122-129 ◽  
Author(s):  
C. M. Bowden ◽  
B. S. Samaga ◽  
W-T. Lyn
Keyword(s):  
Heat Release ◽  
Diesel Engines ◽  
High Speed ◽  
Empirical Scheme ◽  
Rate Of Heat Release ◽  
Semi Empirical ◽  
The Relationship

The rates of injection and heat release of two designs of indirect-injection diesel engines have been studied over a range of speed, load, and timing. The relationship between these two quantities is significantly different from that previously found for open-chamber engines. It is suggested that only part of the air is available for mixing in a divided-chamber engine, and the movement of the piston controls to some extent the availability of the remaining part of the air. A semi-empirical scheme is proposed for relating the rate of injection to the rate of heat release for this type of engine.

An Improved Rate of Heat Release Model for Modern High-Speed Diesel Engines

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Peter G. Dowell ◽  
Sam Akehurst ◽  
Richard D. Burke
Keyword(s):  
Heat Release ◽  
Diesel Engines ◽  
Engine Speed ◽  
Fuel Injection ◽  
Maximum Pressure ◽  
Injection Model ◽  
Wall Impingement ◽  
Small Set ◽  
Rate Of Heat Release ◽  
Engine System

To meet the increasingly stringent emissions standards, diesel engines need to include more active technologies with their associated control systems. Hardware-in-the-loop (HiL) approaches are becoming popular where the engine system is represented as a real-time capable model to allow development of the controller hardware and software without the need for the real engine system. This paper focusses on the engine model required in such approaches. A number of semi-physical, zero-dimensional combustion modeling techniques are enhanced and combined into a complete model, these include—ignition delay, premixed and diffusion combustion and wall impingement. In addition, a fuel injection model was used to provide fuel injection rate from solenoid energizing signals. The model was parameterized using a small set of experimental data from an engine dynamometer test facility and validated against a complete data set covering the full engine speed and torque range. The model was shown to characterize the rate of heat release (RoHR) well over the engine speed and load range. Critically, the wall impingement model improved R2 value for maximum RoHR from 0.89 to 0.96. This was reflected in the model's ability to match both pilot and main combustion phasing, and peak heat release rates derived from measured data. The model predicted indicated mean effective pressure and maximum pressure with R2 values of 0.99 across the engine map. The worst prediction was for the angle of maximum pressure which had an R2 of 0.74. The results demonstrate the predictive ability of the model, with only a small set of empirical data for training—this is a key advantage over conventional methods. The fuel injection model yielded good results for predicted injection quantity (R2 = 0.99) and enabled the use of the RoHR model without the need for measured rate of injection.

Bayesian estimate of pre-mixed and diffusive rate of heat release phases in marine diesel engines

2016 ◽  
Vol 39 (5) ◽  
pp. 1835-1844 ◽  
Author(s):  
Marcelo A. Pasqualette ◽  
Diego C. Estumano ◽  
Fabiana C. Hamilton ◽  
Marcelo J. Colaço ◽  
Albino J. K. Leiroz ◽  
...  
Keyword(s):  
Heat Release ◽  
Diesel Engines ◽  
Bayesian Estimate ◽  
Marine Diesel ◽  
Rate Of Heat Release

A Study on the Numerical Prediction of Heat Release Rate and NOx Production in Medium-Speed Marine Diesel Engines

2003 ◽  
Author(s):  
Joo Youn Kim ◽  
Wook Hyeon Yoon ◽  
Ji Soo Ha
Keyword(s):  
Heat Release ◽  
Diesel Engines ◽  
High Speed ◽  
Digital Camera ◽  
Numerical Results ◽  
Spray Angle ◽  
Nox Formation ◽  
Time Resolved ◽  
Medium Speed ◽  
Marine Diesel

Prediction of the ROHR (rate of heat release) and NOx production in medium-speed marine diesel engines was investigated. The subject of this paper is qualitative and quantitative evaluation of the numerical results. FIRE code v8.1 was used to examine the behavior of spray and combustion phenomena in diesel engine. Wave breakup and Zeldovich models were adopted to describe the atomization characteristics and NOx formation. The spray visualization was performed experimentally in the constant-volume high-pressure chamber to clarify numerical results on the spray characteristics of the spray angle and penetration. Time-resolved spray behaviors were captured by high-speed digital camera. The simulation results were tested with the experimental data of the real engine. Finally, with adjustment of some model constants, reasonable agreements between experimental and simulated results on the ROHR and NOx were shown.

scholarly journals Study of the influence of compression ratio on the rate of heat release in small displacement Diesel engines

2018 ◽  
Vol 11 (21) ◽  
pp. 1-8
Author(s):  
Jorge Duarte Forero ◽  
Guillermo E. Valencia ◽  
Luis G. Obregon ◽  
◽  
◽  
...  
Keyword(s):  
Heat Release ◽  
Compression Ratio ◽  
Diesel Engines ◽  
Small Displacement ◽  
Rate Of Heat Release

Study the Characteristics in the Growth Phase of Wood Crib Fires

2009 ◽  
Author(s):  
Qiang Xu ◽  
G. J. Griffin ◽  
XuHong Miao ◽  
ZhenYu Xu ◽  
Y. Jiang
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Growth Phase ◽  
Mass Loss Rate ◽  
Heat Of Combustion ◽  
Medium Size ◽  
Wood Crib ◽  
Rate Of Heat Release ◽  
The Relationship

Tests were conducted with ISO 9705 room to investigate the combustion behavior of medium size wood cribs. Cribs were burnt at the center and corner inside ISO room and also under the hood of the ISO room. Effective heat of combustion and increase rate of heat release rate in growth phase is compared for cribs with different nominal heat release rate and in different positions. The relationship between scaled steady mass loss rate and porosity factor of wood crib is quite different from those in literatures. The average effect heat of combustion is 12.18 MJ kg−1, which is close to commonly accepted value 12 MJ kg−1 for wood sample burning with diffusion flame.

The Problem of Predicting Rate of Heat Release in Diesel Engines

1969 ◽  
Vol 184 (10) ◽  
pp. 192-202 ◽  
Author(s):  
H. C. Grigg ◽  
M. H. Syed
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Chemical Kinetics ◽  
Diesel Engines ◽  
Turbulent Mixing ◽  
Air Entrainment ◽  
Experimental Results ◽  
Fuel Sprays ◽  
Rate Of Heat Release ◽  
Kinetics Of

Two simple models for the rate of heat release in diesel engines are described. The factors taken into account in the models are rate of entrainment of air into the fuel sprays, the rate of turbulent mixing of fuel and air within the spray, and the chemical kinetics of burning. The models differ in their treatment of the rate of air entrainment. Comparisons are made with experimental results for a diesel engine running at two speeds and a variety of turbocharging ratios. The overall agreement with experiment in respect of shape of rate of heat release diagram is good, with the exception of the naturally aspirated cases where the rate of air entrainment is too low.

Fuel-Forced Flame Response of a Lean-Premixed Combustor

2011 ◽  
Author(s):  
Poravee Orawannukul ◽  
Jong Guen Lee ◽  
Bryan D. Quay ◽  
Domenic A. Santavicca
Keyword(s):  
Heat Release ◽  
Flow Rate ◽  
Equivalence Ratio ◽  
Operating Conditions ◽  
Chemiluminescence Intensity ◽  
Combustion Dynamics ◽  
Lean Premixed ◽  
Flame Response ◽  
Rate Of Heat Release ◽  
The Relationship

The response of a swirl-stabilized flame to equivalence ratio fluctuations is experimentally investigated in a single-nozzle lean premixed combustor. Equivalence ratio fluctuations are produced using a siren device to modulate the flow rate of fuel to the injector, while the air flow rate is kept constant. The magnitude and phase of the equivalence ratio fluctuations are measured near the exit of the nozzle using an infrared absorption technique. The flame response is characterized by the fluctuation in the flame’s overall rate of heat release, which is determined from the total CH* chemiluminescence emission from the flame. The relationship between total CH* chemiluminescence intensity and the flame’s overall rate of heat release is determined from a separate calibration experiment which accounts for the nonlinear relationship between chemiluminescence intensity and equivalence ratio. Measurements of the normalized equivalence ratio fluctuation and the normalized rate of heat release fluctuation are made over a range of modulation frequencies from 200 Hz to 440 Hz, which corresponds to Strouhal numbers from 0.4 to 2.8. These measurements are used to determine the fuel-forced flame transfer function which expresses the relationship between the equivalence ratio and rate of heat release fluctuations in terms of a gain and phase as a function of frequency. In addition, phase-synchronized CH* chemiluminescence images are captured to study the dynamics of the flame response over the modulation period. These measurements are made over a range of operating conditions and the results are analyzed to identify and better understand the mechanisms whereby equivalence ratio fluctuations result in fluctuations in the flame’s overall rate of heat release. Such information is essential to guide the formulation and validation of analytical fuel-forced flame response models and hence to predict combustion dynamics in gas turbine combustors.

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