Defence Research and Development Laboratory

About: Defence Research and Development Laboratory is a facility organization based out in Hyderabad, India. It is known for research contribution in the topics: Turbulence & Mach number. The organization has 404 authors who have published 420 publications receiving 4183 citations. The organization is also known as: DRDL.

Assessment of the Thermal Decomposition and Combustion Behavior of Double-Base Propellants

Abstract: A Knowledge of the role of condensed phase reactions vis-a-vis gas phase reactions in the combustion of a propellant is essential in formulating models for combustion. The salient features of the role of condensed phase reactions in the combustion of solid composite propellants have recently been reviewed by Kishore.1 Briefly, in the case of polystyrene (PS)/ammonium perchlorate (AP) propellants it was inferred from the earlier studies that condensed phase reactions contribute significantly to the total combustion process at ambient pressure.

Numerical Modelling of Liquid Ramjet Combustors

Abstract: The liquid fuel ramjet system employing a subsonic side-dump combustor is simulated inthe present study, and the predictions are compared with the available experimental data. Thecomplex combustion phenomenon in a ramjet combustor has been carried out using probabilitydensity function (PDF) approach. The complexity arises because of the mixing of fuel and airstreams, and the burning of the resultant mixture, within the confined space of the combustionchamber. The predicted numerical results have been validated with the results available in openliterature for a two-dimensional case and with in-house experimental data for a three-dimensionalcase. The methodology allows different designs to be evaluated quantitatively based on theperformance metrics such as combustion efficiency, flame stability, etc.Defence Science Journal, 2008, 58(1), pp.3-14, DOI:http://dx.doi.org/10.14429/dsj.58.1620

Estimation of the Grain Size Number and Microstructure Analysis of AA6061 Alloy Flow Formed Tubes

Abstract: Flow forming process is a chipless metal forming process used for the production of high accuracy axi-symmetrical cylindrical components. During this process there is an increase in tube length and decrease in thickness without any change in internal diameter. Generally forming is performed with a single roller or three rollers over a rotating mandrel and the present work is with three roller setup. The work material is plastically deformed in the radial direction by compression due the rollers and made to flow in an axial direction and the thickness reduction is achieved with single pass. The AA6061 aluminum alloy, usually used in defense components is considered for flow forming. The mechanical properties of this alloy are dependent on the rate at which the alloy is heated and quenched. Solution treatment has been carried out at 400 °C for 2 h followed by quenching in water. Microstructure of the finished product has been studied by using SEM and grain size is estimated for different reduction ratios and stagger distance using the intercept method.

Optimization of cutting parameters for improved machining of Fe-Al alloy

Abstract: Series of machining experiments are conducted on Aluminium-Steel alloy work material using Carbide 45° tool-inserts with an objective to offer a machining solution in the form of optimized cutting parameters that facilitates substantial improvement in tool-life, productivity and machining economy. As the newer alloy overcomes the acute machining obstructions, it qualifies for superior machining and emerges as a futuristic metal in wide spread deserving applications.