NOPR Collection:

CFD study of isothermal flow in an afterburner system

2016-07-20T04:59:43Z

Title: CFD study of isothermal flow in an afterburner system Authors: Ganesan, S; Kumar, S Kishore; Ganesan, V Abstract: This paper focuses a detailed numerical prediction of non-reacting flow analysis in a practical 1/3 scaled model gas turbine afterburner system. The analysis is performed using SIMPLE algorithm in a body-fitted multi-block grid using ST AR-CD software. The turbulence is simulated using standard k-ɛ model. The validation of software is carried out in a afterburner model by comparing axial, radial and circumferential velocities at various axial locations. The agreement between the prediction and experimental data are quite reasonable. The analysis is extended to the flow in a practical afterburner system. The afterburner system consists of an annular diffuser, a complex three-dimensional flame stabilizer, a liner with chute, screech and cooling rings holes and a convergent nozzle. The wall static pressures are compared with experimental data obtained from rig results for both core and bypass casing. The agreement between CFD prediction and experimental data are in close agreement. The predicted length of the re-circulation zone of the lower radial gutter is larger (2.7 times width of the gutter) than upper radial gutter, which is about 2.3 limes width. This is due to combined effect of annular diffuser and lower radial gutter. But the length of the re-circulation zone of the annular ring is slightly less than (0.94 times) the width of the v-gutter. The effect at' different mass flow rates on the afterburner performance is also evaluated and it is observed that mass flow rate does not affect the re-circulation zone characteristics. An increase of 20% in mass flow rate increases the exit nozzle velocity by 35%. Page(s): 487-497

A new design proposal for intelligent routers to avoid congestion in TCP/IP networks

2016-07-20T04:58:18Z

Title: A new design proposal for intelligent routers to avoid congestion in TCP/IP networks Authors: Pujeri, Ramachandra V; Sivanandam, S N Abstract: In this paper, the various methods to detect network congestion and a method to avoid and recover from such congestion are discussed. This is a proposal to embed intelligence within routers, which will enable them to periodically check each of their communication paths for congestion and correspondingly update their router table and heuristic knowledge base. This is done using a new artificial intelligence concept called the software agents. This method provides a level of abstraction thereby minimizing the visible complexity, so that the source and destination can be designed more easily. Page(s): 481-486

Phase transition in Pb[(Mg_3/4Cu_1/4)_1/3Nb_2/3]O₃ ceramic

2010-04-29T16:30:46Z

Title: Phase transition in Pb[(Mg_3/4Cu_1/4)_1/3Nb_2/3]O₃ ceramic Authors: Kumar, Amit; Prasad, K; Choudhary, S N; Sinha, T P Abstract: Single phase perovskite-type cubic ceramics of Pb[(Mg_3/4Cu_1/4)_1/3Nb_2/3]O₃ (PMCN) were synthesized by high temperature double step solid state reaction technique. Dielectric studies show relaxor behaviour with diffuse phase transition. The phase transition (T_m) occurs at -22°C at 10 kHz. The frequency dependence of T_m has been modeled using Vogel-Fulcher relation. The dielectric relaxation in PMCN is found analogous to the magnetic relaxation in spin-glass system. The relaxor behaviour in PMCN has also been examined through admittance spectroscopy. Page(s): 586-590

Flexural vibrations of non-homogeneous elliptic plates

2010-04-29T16:30:36Z

Title: Flexural vibrations of non-homogeneous elliptic plates Authors: Chakraverty, S; Jindal, Ragini; Agarwal, V K Abstract: The effect of non-homogeneity of material for complex shaped plates on their vibration frequencies is analyzed. Corresponding mathematical model has been developed. The results have been included for the first few frequencies of the plate element that are important to know before finalizing the design of a structure. Rayleigh Ritz method with generation of orthogonal polynomials using Gram-Schmidt process is used. In the numerical results, present solution is carefully examined by a convergence test and comparison with known results for special cases are carried out. Page(s): 521-528

NOPR Collection:

CFD study of isothermal flow in an afterburner system

A new design proposal for intelligent routers to avoid congestion in TCP/IP networks

Phase transition in Pb[(Mg3/4Cu1/4)1/3Nb2/3]O3 ceramic

Flexural vibrations of non-homogeneous elliptic plates

Phase transition in Pb[(Mg_3/4Cu_1/4)_1/3Nb_2/3]O₃ ceramic