Author: Cody William SquibbPublisher:
ISBN:
Category : Diesel motor
Languages : en
Pages : 216
Book Description
Diesel Combustion and Fuel Spray Analysis Using an Optical Engine with Pressure Diagnostics, Infrared Thermography, and High-speed Photography
Author: Cody William SquibbPublisher:
ISBN:
Category : Diesel motor
Languages : en
Pages : 216
Book Description
Design and Implementation of an Infrared Diagnostic Systems to a High Speed Small Bore Diesel Engine
Author: William Edward ChurchPublisher:
ISBN:
Category :
Languages : en
Pages : 110
Book Description
Using Optical Engine Combustion Diagnostics to Study Diesel Injectors
Author: Stephen A. CiattiPublisher: LAP Lambert Academic Publishing
ISBN: 9783838338682
Category :
Languages : en
Pages : 212
Book Description
A study was undertaken to study several diesel injector nozzles that produced different engine emissions performance. The nozzle styles used were two valve covered orifice (VCO) type nozzles that were manufactured using two different techniques, and two mini-sac nozzles that provided a point of comparison. The VCO nozzles and one mini-sac nozzle had 200 micron holes, while the other mini-sac nozzle had 160 micron holes. The nozzles were otherwise identical in all respects, such as orifice diameter, l/d, etc. The injector used was a cam pressurized EUI. Fired experiments were conducted on a Detroit Diesel Series 50 engine. Optical access was obtained by inserting a sapphire window in place of one of the exhaust valves. Under high speed, high load, retarded injection timing conditions, it was discovered that each nozzle produced different soot and NOx emissions. Pressure and heat release data, along with high-speed film images were obtained. It was discovered that the temperature and KL factor results from the 2-color optical pyrometry showed significant differences between the nozzles.
Combustion and Spray Visualization in a High-speed Direct-injected Engine
Author: Aakash PuntambekarSpectral IR Images of Direct-Injection Diesel Combustion by High-Pressure Fuel Injection
Author: E. ClasenPublisher:
ISBN:
Category :
Languages : en
Pages : 14
Book Description
Instantaneous successive spectral infrared (IR) images were obtained from a spray plume in a direct injection (DI) type compression-ignition (Cl) engine during the compression and combustion periods. The engine eqwpped with a high pressure electronic-controlled fuel injector system was operated by using D-2 Diesel fuel. In the new imaging system used for the present study, four high-speed IR cameras (with respective band filters in front) were lined up to a single optical arrangement containing three spectral beam splitters to obtain four spectral images at once. Two band filters were used for imaging the water vapor distribution and another two band filters were placed for capturing images of combustion chamber wall or soot formation. The simultaneous imaging was successively triggered by signals from an encoder connected to the engine. The fuel injection parameters were precisely controlled and the pressure-time (p-t) history was obtained for individual sets of images. The start of fuel injection was varied through four different crank angle positions. Mentioning some results from the study, the spectral IR images had no resemblance with the ones obtained using a visible-range camera from a comparable engine system as reported by others. In general, the present spectral images taken at the same crank angle were not mutually comparable.
Analysis of Combustion and Flow Diagnostics
Author: Publisher: SAE International
ISBN:
Category : Science
Languages : en
Pages : 212
Book Description
Advanced Diagnostics for High Pressure Spray Combustion
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 37
Book Description
The development of accurate predictive engine simulations requires experimental data to both inform and validate the models, but very limited information is presently available about the chemical structure of high pressure spray flames under engine- relevant conditions. Probing such flames for chemical information using non- intrusive optical methods or intrusive sampling techniques, however, is challenging because of the physical and optical harshness of the environment. This work details two new diagnostics that have been developed and deployed to obtain quantitative species concentrations and soot volume fractions from a high-pressure combusting spray. A high-speed, high-pressure sampling system was developed to extract gaseous species (including soot precursor species) from within the flame for offline analysis by time-of-flight mass spectrometry. A high-speed multi-wavelength optical extinction diagnostic was also developed to quantify transient and quasi-steady soot processes. High-pressure sampling and offline characterization of gas-phase species formed following the pre-burn event was accomplished as well as characterization of gas-phase species present in the lift-off region of a high-pressure n-dodecane spray flame. For the initial samples discussed in this work several species were identified, including polycyclic aromatic hydrocarbons (PAH); however, quantitative mole fractions were not determined. Nevertheless, the diagnostic developed here does have this capability. Quantitative, time-resolved measurements of soot extinction were also accomplished and the novel use of multiple incident wavelengths proved valuable toward characterizing changes in soot optical properties within different regions of the spray flame.
Investigation of Fuel Effects and Identification of Representative Behavior of Reacting Fuel Sprays
Author: James P HubnerPublisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 0
Book Description
The efficiency and energy density of compression ignition (diesel) engines powered by liquid fuels make them irreplaceable in many applications, and technological and regulatory changes necessitate use of new biofuels and combustion modes to realize the economic and efficiency benefits of diesel engines with reduced emissions. To address these requirements new measurement techniques -- particularly high spatial resolution, high acquisition rate, non-intrusive optical diagnostics -- together with advanced modelling are used to investigate combustion phenomena. The purpose of this research is to implement novel optical diagnostics and analysis techniques to report high-quality data to advance understanding of transient fuel sprays and combustion, and provide improved guidance to facilitate fuel screening and combustion modelling efforts. First, the largest published data-set of diesel-like injections at a single operating condition was collected and analyzed with multiple, simultaneous optical techniques -- Rainbow Schlieren Deflectometry (RSD) and OH* chemiluminescence imaging -- to quantitatively describe a reacting jet. This uniquely large data-set was collected with a constant-pressure flow chamber maintaining diesel-like conditions and flushing combustion products for a high experimental repetition rate. First-stage combustion is described with RSD for the first time, and it is demonstrated that larger data-sets than found elsewhere in literature are required to achieve statistically stationary results. Secondly, primary reference fuels are investigated using aforementioned techniques, a novel two-color pyrometry system, and newly developed analysis techniques to determine Apparent Turbulent Flame Speed (ATFS), an important combustion parameter linked closely to both fuel characteristics and localized turbulent mixing. Third, these techniques were applied to candidate biofuels identified by the Co-Optima project. To improve visualization in cyclic, turbulent combustion, a custom metric was implemented to identify a single, representative injection from each case to facilitate analysis without the over-smoothing effects of image (ensemble) averaging; this greatly improved the ability to differentiate premixed versus diffusion-dominated sooting modes of combustion. Fuel oxygenation and volatility were shown to be significant factors effecting liquid length, mixing behavior, and sooting. The last part of this research details, with a large and statistically significant data-set, the injection-to-injection variation observed by multiple diagnostics between events at identical ambient conditions. Rigorous analysis shows that these fluctuations are due solely to the stochastic nature of turbulence, necessitating the custom metric used in the previous study. That metric is then detailed, producing a new manner in which analysis of transient, turbulent, reacting jets can be accomplished for improved results and reliability.
Combustion and flow diagnostics
Author: SAE.Improved Two-Color Pyrometry Diagnostic for Spatiotemporally-Resolved Measurements in Diesel-Like Fuel Sprays
Author: Shawn Andres ReggetiPublisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 0
Book Description
The compression ignition (diesel) engine continues to be an attractive option for vehicle powertrains, particularly in heavy- and medium-duty transportation. While offering many operational advantages including a high power output per unit weight, quick refueling capabilities, and reliability; the diesel engine is prone to produce significant emissions. Chief among these emissions are soot and nitrogen oxides (NOx). Combustion techniques that reduce soot tend to increase NOx and vice versa requiring an acceptable soot-NOx tradeoff. The optimization of this tradeoff has been a challenge in recent decades with the advent of advanced combustion strategies and alternative fuels. Soot measurements at engine relevant conditions are the focus of this work and critical to building understanding of these complex phenomena and to evaluate potential solutions. Two-color pyrometry (2CP) has been used over several decades to study engine-relevant combustion processes, but results are generally regarded as qualitative or semi-quantitative. The objective of this work is to advance the 2CP diagnostic to achieve reliable, spatially-resolved measurements of the soot in diesel-like fuel sprays. This outcome is accomplished by 1) developing a new optical design for 2CP to overcome common measurement errors in other designs, 2) performing a detailed uncertainty analysis to quantify errors, and 3) applying the new 2CP system to statistically analyze the soot behavior in a diesel-like fuel spray. First, a novel optical configuration was developed and constructed from off-the-shelf components to eliminate systematic errors of previous designs. In many current 2CP systems, large measurement errors can be introduced by parallax because lines of sight (LsOS) of the two wavelengths are not the same. The modified optical hardware, was shown to accurately resolve corresponding pixels at both wavelengths of a high-resolution optical target, indicating that the LsOS for both wavelengths are the same. Next, an experimental investigation of reacting diesel-like fuel sprays revealed steady experiment conditions with repeatable global parameters of combustion. Despite the similarity of global behavior across injections, significant spatial variation of soot was observed between repeated injection experiments. Computed average turbulent flame speed for each injection suggests that initial reaction rates, which are a function of local equivalence ratio, determine the variation. Motivated by the spatial variations of soot observed across injections, the 2CP technique was further refined for quantitative, spatially resolved measurements. A pixel-by-pixel calibration was applied to account for any non-uniformities in sensor response, increasing accuracy of the computed soot quantities at each pixel. Uncertainty analysis determined the reliability of each individual measurement. This study found that the largest relative uncertainties are associated with low soot concentrations. Highly uncertain soot measurements typically occur on the edges of the diffusion flame where is soot is most likely to be oxidized. However, these highly uncertain data had marginal impact on the total soot mass produced in the flame. Finally, a large 500-injection data set employed all the previously developed 2CP diagnostic capabilities to evaluate spatiotemporal sooting behavior in a diesel-like spray flame. Focusing on the gaps in the literature for temporal development of soot and detailed study of the statistical variability between injections, this work provides insights on soot formation in key regions: lift-off, core, and jet head. Total soot contribution from binned individual soot mass values indicate that large soot masses take longer to form, but are the first to oxidize. Overall, the majority of injections produced low soot, but a few produced exceptionally high soot by comparison.