| 000 -LEADER |
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| fixed length control field |
04427nam a22001577a 4500 |
| 082 ## - DEWEY DECIMAL CLASSIFICATION NUMBER |
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| Classification number |
621 |
| 100 ## - MAIN ENTRY--PERSONAL NAME |
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| Personal name |
Janjua, Asad Asghar |
| 245 ## - TITLE STATEMENT |
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| Title |
A Novel Algorithm for Evaluating the Accuracy of In-Cylinder Convective Heat Transfer Coefficient Estimation Models in Port Water-Injected Diesel Engine / |
| Statement of responsibility, etc. |
Asad Asghar Janjua |
| 264 ## - PRODUCTION, PUBLICATION, DISTRIBUTION, MANUFACTURE, AND COPYRIGHT NOTICE |
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| Place of production, publication, distribution, manufacture |
Islamabad : |
| Name of producer, publisher, distributor, manufacturer |
SMME- NUST; |
| Date of production, publication, distribution, manufacture, or copyright notice |
2025. |
| 300 ## - PHYSICAL DESCRIPTION |
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| Extent |
118p. |
| Other physical details |
Soft Copy |
| Dimensions |
30cm |
| 500 ## - GENERAL NOTE |
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| General note |
This research study focuses on evaluating the accuracy of three classical empirical<br/>models (Eichelberg, Woschni, and Hohenberg Models) commonly used to estimate the<br/>in-cylinder gas-to-wall spatially-averaged-instantaneous-convective heat transfer<br/>coefficient (HTC) in a four-stroke high-speed diesel (HSD) engine. The investigation<br/>specifically examines effects of port water injection on HTC at low, part, and high load<br/>conditions using a retrofitted port water injection system capable of generating variable<br/>water injection rates. The absence of a reliable accuracy determination experimental<br/>methodology for HTC models in port water injected-diesel engines has prompted the<br/>development of an algorithm. This approach utilizes a novel model-based, sequential<br/>flow approach using experimental data to develop an algorithm for determination the<br/>accuracy of HTC models. The primary data source consists of 36000 experimentally<br/>measured in-cylinder pressure values, obtained at 0.36-degree intervals. Separate pressure<br/>measurements were conducted for each of the three loading conditions, with six<br/>variations in water injection rates within each condition. The algorithm follows a twostep process. First, thermodynamic models are employed to derive essential parameters<br/>such as in-cylinder volume, temperature, internal energy, thermodynamic work, and<br/>exhaust heat. In the second step, the algorithm calculates the in-cylinder convective heat<br/>transfer coefficients using the Eichelberg, Woschni, and Hohenberg models. Notably,<br/>these models yield different HTC values for identical engine operating conditions and<br/>water injection rates. Using the derived HTC values, the algorithm calculates the heat<br/>loss to the cylinder walls, enabling the determination of the engine's cumulative heat<br/>release based on thermodynamic relations involving internal energy, work, exhaust heat,<br/>and heat loss. By comparing the fuel cumulative heat release with the engine cumulative<br/>heat release, the algorithm calculates the engine's combustible efficiency. To identify the<br/>heat transfer coefficient model that closely matches a reference value of 98% for engine<br/>combustible efficiency, the algorithm compares the calculated values from all testing<br/>conditions. The model that generates the highest number of occurrences closest to the<br/>referenced 98% is considered the most accurate heat transfer coefficient estimation model<br/>xix<br/>for high-speed diesel engines utilizing port water injection. The algorithm was<br/>implemented on the data obtained from three operating conditions. Each operating<br/>condition was tested without water injection and five water injections rates using<br/>successive increase in water mass. Total of 36000 in-cylinder pressure values were used<br/>for each operating condition and at each water injection rate to obtain all thermodynamic<br/>values used in the research. This led to 54 engine combustible values. These engine<br/>combustible values then provided 18 most accurate values corresponding to 18 water<br/>injection rates for three engine operating conditions. The accuracy of each HTC model<br/>was estimated by algorithm at each operating condition and for entire engine operation as<br/>well. According to reference value of 98% combustible efficiency; the algorithm<br/>calculated that at low and high loading conditions, Hohenberg model estimated most<br/>accurate HTC values with 66.66% and 100% accuracy. At medium loading condition,<br/>Woschni model estimated most accurate HTC values with 66.66% accuracy. According<br/>to algorithm, Hohenberg model estimated HTC values with 67% accuracy for overall<br/>engine operation. This research addresses a critical gap in accurately estimating HTC in<br/>water-injected diesel engines and provides valuable insights for optimizing engine<br/>performance. |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM |
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| Topical term or geographic name entry element |
PhD in Mechanical Engineering |
| 700 ## - ADDED ENTRY--PERSONAL NAME |
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| Personal name |
Supervisor : Dr. Waqas Khalid |
| 856 ## - ELECTRONIC LOCATION AND ACCESS |
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| Uniform Resource Identifier |
<a href="http://10.250.8.41:8080/xmlui/handle/123456789/54838">http://10.250.8.41:8080/xmlui/handle/123456789/54838</a> |
| 942 ## - ADDED ENTRY ELEMENTS (KOHA) |
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| Source of classification or shelving scheme |
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| Koha item type |
Thesis |
