http://nopr.niscpr.res.in/handle/123456789/7202 2026-10-09T07:42:13Z http://nopr.niscpr.res.in/handle/123456789/7626 Title: A combined CFD and network approach for a simulated turbine blade cooling system Authors: Kumar, B V N Rama; Prasad, B V S S S Abstract: A combined computational fluid dynamics (CFD) and network analysis is proposed as an approach to solve complex flow and heat transfer problems. Perforated cylindrical passages with impingement and film cooling arrangement in a circular cylinder are considered as an example for demonstrating the methodology and simulated a cooled turbine blade geometry. Two networks namely, flow and thermal networks are developed. CFD calculations are performed to estimate loss factors and thermal resistances, which are used as input to the flow and thermal networks. Iterative procedures are adopted for solving the networks. Results of the pressure and temperature at different nodes, flow rates through the elements and film hole effectiveness in the span-wise and peripheral directions are presented at selected positions for different pressure inlet conditions of coolant. The results indicate that 0.15% increase in coolant to mainstream flow ratio causes 20% reduction in coolant outlet temperature and 25% increment in film cooling effectiveness. Page(s): 195-201 2006-06-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/7595 Title: Response of thin film Al₂O₃ optical waveguide to moisture in paper Authors: Puri, R K; Puri, Vijaya Abstract: The response to paper moisture of thin film Al₂O₃ optical waveguide has been studied. The changes in the transmission of thin film optical waveguide due to changes in relative humidity of paper used as in touch overlay have been reported in this paper. The output decreases due to the overlay of paper. The transmission of the waveguide depends on the moisture content, texture and colour of the paper. Higher moisture content in paper tends to saturate the waveguide output. The sensitivity to moisture changes and type of paper is more for lower moisture content. Hysteresis is observed due to all the papers studied. The larger sensitivity in the lower moisture range may provide a means for detecting and controlling moisture in paper for packing, printing and other applications, as this overlay method requires only a small piece of paper. Page(s): 549-551 2006-12-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/7594 Title: New pathway for quick estimation of gas phase heat of formation of non-aromatic energetic compounds Authors: Keshavarz, M H; Tehrani, M Kavosh; Pouretedal, H R; Semnani, A Abstract: A new theoretical approach is presented for calculation of gas phase heats of formation of non-aromatic energetic compounds. It is based on elemental composition and various functional groups of C_aH_bN_cO_d non-aromatic energetic compounds. Gas phase heats of formation for 85 non-aromatic energetic compounds are compared with experimental data as well as semi-empirical quantum mechanical PM3 prediction. Root mean square (rms) of deviation for some of them, where experimental data are available, shows 5.1 and 6.7 kcal/mol for new and semi-empirical quantum mechanical PM3 methods respectively. Page(s): 542-548 2006-12-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/7593 Title: Friction and slide wear characteristics of glass-epoxy and glass-epoxy filled with SiCp composites Authors: Suresha, B; Chandramohan, G; Sadananda Rao, P R; Sampathkumaran, P; Seetharamu, S; Venkateswarlu, Vartha Abstract: This paper highlights the friction and wear behaviour of glass-epoxy (G-E) composites with and without silicon carbide particles (SiCp) filler content as a function of sliding distance, keeping the sliding velocity and applied load constant. It is seen that the wear rate increases with increasing sliding distance, but the gradient is not maintained the same all through. An attempt has also been made to correlate the wear loss of the worn surfaces using scanning electron microscopic (SEM) observations. The coefficient of friction is found to be almost same over a wide range of sliding distance employed. Further, the study<i style=""> </i>indicates that the SiCp-G-E composites show lower coefficient of friction and lower slide wear loss compared to G-E composites irrespective of the sliding distance employed. It is found that during the running in wear, the wear of the resin mix as well as very few broken fibers are noticed. The breakage of fibers, the matrix debris formation and interface separation take place at a much later stage (i.e., in the severe wear region). In the steady state region some of the broken fibers are getting disoriented in the matrix and also agglomerations of the debris are seen. Other interesting SEM features have been noticed and discussed taking into account the addition of SiCp filler content (2.5 and 5.0 wt. %). Page(s): 535-541 2006-12-01T00:00:00Z