انواع کتب حدیث: لفظی و معنوی موزونیت

The obeisance of Holy Prophet (S. A. W) is the path of forgiveness and essential component of faith. Therefore, the series of preservations of, (RA) Sahabah by continued is (صلى الله عليه وسلم) Prophet Holy of actions and sayings the followers of Ṣaḥābah and Scholars of the Ummah. For worldly and eternal saving, disciplined efforts were carried out in order to preserve this series. This methodology of preservation with extreme care and technique is exemplary. The process for collection of Hadith was initiated and shaped into books and volumes. It is due to the dignified status of Hadith that Allah created such individuals who preserved the sayings of Holy Prophet (ﷺ) with religious fervor, zeal, honesty and great care. In this article meaningful analysis has been given for such important terminologies which convey technically internal characteristics of the series of books and are a great source of literary beauty. In this connection, terminologies and their meanings represent reflection of each other. The basis of these terminologies is not only on estimated ideas but on the literary and intellectual facts. These are not only according to the time and age but also historical and geographical according to the need of hour and circumstances. From Muḥaddithīn’s point of view, these collections have certain benefits and purposes due to which they kept naming them. The brief, simple and understandable words of terminologies are common; however, their purpose is not common. It is distinguished and extra ordinary. The words used in terminologies are not special but purpose is not to express application. Their contextual meaning is taken under consideration instead of the literal one.

Improved Technique for the Calculation of Heat Transfer in a Thrust Chamber

Advancements in rocket propulsion have been the key factor for the scientific progress especially in space exploration and communication. The continued quest to achieve higher propulsion velocities at low cost still provides the room to the scientists and engineers to work on the development in the design of thrust chamber of a rocket engine. Given the high manufacturing and operational cost of rocket engines, precise knowledge of the chamber dynamics, propellants flow and feed system, heat transfer and structural integrity are important. During operations the thrust chamber experiences high temperatures and pressures, thus a reliable design requires adequate knowledge of the flow and combustion physics inside the chamber. A number of ways have been employed by the researchers to optimize heat transfer and performance of the engine. Generally regenerative cooling along with film cooling are used for safe operation.For small LPREs with small mass flow rates of the coolant, safety of the chamber wall becomes challenging job. Structural integrity can be attained by specific heat transfer rate and efficient combustion will give better performance. Numerical estimation of heat transfer using commercial software may be help for design and mounting instrumentation for experimentation at proper place. However one requires an integrated design tool for designing a thrust chamber with optimal performance ensuring adequate thrust, structural integrity and efficient cooling. For optimization of such a thrust chamber, couple fluid-structure-heat transfer analysis is often complicated and requires huge computational resources using commercial software. The combustion chemistry is often approximated through one dimensional theory. Generally experimental/empirical correlations are used for heat transfer rate calculations or one has to rely on expensive testing to validate structural design and safe operation. However the high cost involved with experimentation and manufacturing of even a small chamber, an integrated tool for optimal design of thrust chamber can be helpful. The optimized geometry can be numerically simulated for confirmation before leading to actual use. The integrated design tool can help in obtaining optimal thrust under given dimensional and flow constrains with adequate heat transfer rates ensuring low design cost. The major aim of this research work was to develop an in-house integrated software tool for the design and optimization of the coolant channel configuration of thrust chamber of a rocket engine. However, the study also includes the experimentation and CFD study for the validation of the tool developed. The developed integrated tool includes seven modules providing optimal performance parameters for a given thrust chamber design. The modules include combustion chemistry, flow dynamics, heat transfer and optimal cooling channels design for a given thrust chamber shape. Here the results obtained from the integrated tool have been verified using own computational fluid dynamics results and experimental data as well as the published results available in the literature. Amongst the important parameters, heat transfer rate within the thrust chamber is key design parameter. Here focus is on the prediction of heat transfer rates and surface temperatures of both coolant and thrust chamber. Thus results for the heat transfer rates and heat transfer coefficients are compared with published results, numerical simulations and experimental data. Further calculations for the optimized coolant geometry have been carried out based on the heat transfer, flow rate and pressure drop across the coolant channel. The results indicate that the predicted geometry offers safe operation of the thrust chamber. The integrated tool developed in this study is intelligent enough to optimize a number of coolant channel flow configurations with different coolants and fuels within a short time.