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Indian Journal of  Engineering & Materials Sciences

 

 

 

ISSN : 0971-4588

 

CODEN : IEMSEW

VOLUME 11

NUMBER 2

APRIL 2004

 

CONTENTS

 

 
Engineering
 

 

 

Loss factor for a clamped edge circular plate subjected to an eccentric loading

79

M K Gupta & S P Nigam

 

[IPC Code: Int. Cl.7 G 01L 1/00]

 

 

 

Investigation of the flow field in the various regions of intake manifold of a S.I. engine

85

S C Kale & V Ganesan

 

[IPC Code: Int. Cl.7 F 02B 29/02; F 15D 1/00]

 

 

 

Flow through S.I. engine air intake system using CFD at part throttle and full throttle

 93

J Suresh Kumar & V Ganesan

 

[IPC Code: Int. Cl.7 F 02B 29/02; F 15D 1/00]

 

 

 

Experimental investigation on the supersonic jet impingement

 100

P M Ghanegaonkar, V Ramanujachari & S Vijaykant

 

[IPC Code: Int. Cl.7 F 15D 1/08]

 

 

 

Variation effects on the economical design of service reservoirs

 107

Devendra Swaroop Bhargava & Promod Kumar Gupta

 

[IPC Code: Int. Cl.7 E 03B 11/16]                                     

 

 

 

Materials Science

 

 

 

Influence of sliding velocity on wear behaviour of different microstructures of Ni-Cr-Mo-V steel

 113

D Rai & J P Pathak

 

[IPC Code: Int. Cl.7 C 22C 38/00]

 

 

 

Laser-induced phosphorescence studies of doubly-doped CaS phosphors

 121

H S Bhatti, Rajesh Sharma, N K Verma & Sunil Kumar

 

[IPC Code: Int. Cl.7 C 09K 11/60; C 09K 11/84]

 

 

 

Determination of thermal conductivity of high porosity organic foams at varying temperatures and pressures using thermal probe method

 125

Jagjiwanram & Ramvir Singh

 

[IPC Code: Int. Cl.7 G 01N 25/18]

 

 

 

Studies on structural, optical and photoelectron transportation in solution grown nanosize CdS thin films for photosensor application

 130

S D Chavhan, S V Bagul, A R Patil & R P Sharma

 

[IPC Code: Int. Cl.7 H 01L 31/0296]

 

 

Thermoluminescence response of some common brands of iodised salts

 137

R K Gartia, B Arunkumar Sharma & Usham Ranita

 

[IPC Code: Int. Cl.7 F 21K 2/04]

 

 
Note

 

A simple method to evaluate the critical loads of cantilever columns with follower forces

 143

K Kanaka Raju & G Venkateswara Rao

 

[IPC Code: Int. Cl.7 B 66C 23/18]

 

 

IPC: International Patent Classification

Int. Cl7. : International Classification 7th edition, 1999

 

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 11, April 2004, pp. 79-84

 

Loss factor for a clamped edge circular plate subjected to an eccentric loading

M K Gupta & S P Nigam

 

Present article deals with the analytical evaluation of modal loss factor of a clamped edge thin circular plate of uniform thickness subjected to an eccentric harmonic point load. Starting with the fundamental equation of forced transverse vibration of a thin elastic plate in terms of Green’s function; the expression for the deflections is determined. Stresses are calculated with the help of general stress-deflection equations and the modal loss factor is evaluated at resonance condition. The nodal circles’ radii are also determined analytically for each mode shape.

 

IPC Code: Int. Cl.7 G 01L 1/00

 

 

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 11, April 2004, pp. 85-92

 

 

investigation of the flow field in the various regions of intake manifold of a s.i. engine

S C Kale & V Ganesan

 

The main objective of the present work is to make a computational study of steady flow through intake manifold, port, valve and valve seat of a S.I. engine for various valve lifts. Three-dimensional flow within the manifold, port and valve has been simulated using the computational fluid dynamics (CFD) using the code STAR-CD. Flow field details in the identified regions in the manifold for the various valve lifts have been predicted. Analysis has been carried out for runners 1 and 3 at three different valve lifts for various speeds at wide-open throttle condition. A trimmed cell (adjust and cut process based on an underlying structured grid) has been adopted for meshing the geometries. Flow has been simulated by solving governing equations, viz., conservation of mass and momentum using the SIMPLE-algorithm. Turbulence has been modeled by high Reynolds number version of k-e model. Mass flow rate measurements have been made for validating the numerical prediction. A reasonably good agreement has been obtained between predicted and the experimental results. Also, it is seen that valve lift has a predominant effect on flow structure and it is found that with increase in valve lift there is a tendency for flow separation near the valve seat region.

IPC Code: Int. Cl.7 F 02B 29/02; F 15D 1/00

 

  

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 11, April 2004, pp. 93-99

 

Flow through s.i. engine air intake system using cfd at part throttle and full throttle

J Suresh Kumar & V Ganesan

 

The objective of present study is to predict and analyze the flow through the SI engine air intake system using Computational Fluid Dynamics (CFD) and to validate the prediction by experimental data. Three-dimensional model of air intake system was analyzed by using the commercially available FLUENT software. The mesh was generated using the Tet-hybrid scheme which includes primarily of tetrahedral mesh elements but may include hexahedral, pyramidal and wedge elements. The pressure boundary conditions were used to define the fluid pressure at the inlet and outlet of Air Intake System. In the present study, the CFD code was validated by the experimental work. Experimental data was generated at one bar outlet pressure for the part throttle and full throttle conditions. The CFD plots give informative pictures of the flow field, which will help the designer to understand the effect of various components of Air Intake System. The predicted airflow rate shows good agreement with the experimental results. The results indicate that the CFD model can be used as a tool to understand the effect of various parts of air intake system for optimization. This in effect will reduce the number of experiments to be carried out for arriving at final optimized system.

IPC Code: Int. Cl.7 F 02B 29/02; F 15D 1/00

 

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 11, April 2004, pp. 100-106

 

Experimental investigation on the supersonic jet impingement

P M Ghanegaonkar, V Ramanujachari & S Vijaykant

 

In order to understand the effects of supersonic jet impingement, static tests are conducted in a small-scale rocket motor loaded with a typical nitramine propellant to produce a nozzle exit Mach number of 3. This jet is made to impinge on a plate aligned vertically to the nozzle axis. The distance between the nozzle exit and the plate is varied from 2 to 6 times the nozzle exit diameter. The pressure rise due to jet impingement on the plate has been measured using pressure transducers located at ten different radial locations. The pressure - time data are analyzed to get an insight into the flow field upstream of the plate. The maximum pressure exerted on the plate is about 20-30% of the maximum pressure generated in the combustion chamber. Ten static tests are carried out to obtain the effects of nozzle divergence angle, axial distance between the nozzle exit and the plate and the chamber stagnation pressure on the flow field.

 

IPC Code: Int.Cl.7 F15D 1/08

 

  

 

 

Indian Journal of Engineering & Materials Sciences

 Vol. 11, April 2004, pp. 107-112

 

Variation effects on the economical design of
service reservoirs

Devendra Swaroop Bhargava   &  Pramod Kumar Gupta

 

The equalizing capacity component of the service reservoirs governs the economy of the service reservoirs. It is desirable to evaluate such a capacity accurately for a given type of community and its nature of activities. A methodology to evaluate such an economical capacity is discussed through a comprehensive analysis of the varying situations such as the hours of the pumping schedule, time of starting the pump, and nature of the activities of the populations involved. The presented tabular data and monographs shall be of immense help and use to the designers and operating engineers for fixing the hours of pumping and the schedule of pumping operation.

 

IPC Code: Int. Cl.7 E 03 B 11/16

 

 

 

Indian Journal of Engineering & Materials Sciences

 Vol. 11, April 2004, pp. 113-120

 

 

Influence of sliding velocity on wear behaviour of different microstructures of Ni-Cr-Mo-V steel

D Rai & J P Pathak

 

The effect of sliding velocity on wear property of six microstructural states of Ni-Cr-Mo-V crane wheel steel under 4 kg load has been studied and discussed in detail. The steel with 0.35 wt.% C, 0.68 wt.% Mn, 0.30 wt.% Si, 0.014 wt.% S and P, 0.68 wt.% Cr, 3.10 wt.% Ni, 0.40 wt.% Mo, 0.11 wt.% V, balance iron was hardened and tempered at 225, 350, 450 and 550°C to develop martensite and various hardened and tempered martensite microstructures. With the help of controlled furnace cooling, a bainitic structure was also developed. It was found that an increase in the tempering temperature increased percentage elongation and reduction in area but decreases the tensile strength. It was observed that increasing the velocity increased the wear rate but beyond a certain sliding rate, wear decreased with an increase in sliding velocity. Wear mechanism changed from mild/oxidative to severe/metallic and then to oxidative with increasing the sliding velocity. Hardened martensite showed highest wear resistance compared with various tempered martensite. Martensite tempered at a lower temperature possessed a higher wear resistance as compared to martensite tempered at a higher temperature. The bainitic microstructure showed the highest wear rate in all cases irrespective of velocity.

 

IPC Code: Int.Cl.7 C22C 38/00

 

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 11, April 2004, pp. 121-124

 

 

Laser-induced phosphorescence studies of doubly-doped CaS phosphors

H S Bhatti,  Rajesh Sharmaa  N K Verma & Sunil Kumar

 

Effect of killer impurities (Fe, Co and Ni) on excited state life-times in CaS phosphors, doped with copper and having variable concentrations of iron, cobalt and nickel has been studied in this paper. The phosphors have been synthesized, and, then using a nitrogen laser as the excitation source, their decay-curve analysis has been done. Various strong emissions have been detected and the corresponding excited state life-time values  measured. These studies are conducted at room temperature. Very interesting results are obtained with the addition of killer impurities in the phosphors with single impurity. Life-time values found to decrease appreciably with the addition of killer impurities (at lower concentration) in the singly doped phosphors. These studies are important as the excited state life-time of the sulphide phosphors prepared by flux method converge to the longer side only, but with the addition of killer impurities at a particular concentration, values of the life-times decreases up to large extent. At higher concentration of killer impurities deeper traps contribute to the phosphorescence, leading to the much higher increase in life-time values.

 

IPC Code: Int. Cl.7 C 09 K 11/60; C 09 K 11/84

 

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 11, April 2004, pp. 125-129

 

Determination of thermal conductivity of high porosity organic foams at varying temperatures and pressures using thermal probe method

Jagjiwanram & Ramvir Singh

 

The thermal conductivity of organic foams at varying temperatures (-20 to 30°C) and interstitial air pressures has been measured using thermal probe method. Experiment has been conducted on different cell sizes of organic foam samples covering a vide range of porosities. Results show that the effective thermal conductivity decreases with increasing porosity and increases by increasing temperature and interstitial air pressure values. Data obtained from the experiment has been compared with the reported model and found good agreement between experimental and theoretical results at room temperature and normal pressure.

 

IPC Code: Int. Cl.7 G01N 25/18

 

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 11, April 2004, pp. 130-136

 

Studies on structural, optical and photoelectron transportation in solution grown nanosize CdS thin films for photosensor application

S D Chavhan, S V Bagul, A R Patil & R P Sharma

 

CdS Thin films of different thicknesses have been deposited onto glass substrates at 60°C.The source materials for Cd and S have been used as CdCl2 and NH2-CS-NH2 in ammonia solution respectively. The reaction mechanism involved the preparation of film onto precleaned glass substrate through Cd2+ and S2 ions in aqueous solution. Deposited thin films were annealed in air from 50 to 450oC. The XRD results are presented only for the films annealed from 300 to 450oC, as below 300oC there is no appreciable change in crystal structure. From the XRD patterns, films are seen to be polycrystalline in nature with the formation hexagonal phase. The crystallinity of the films was improved by annealing in air at 400°C. The optical transmittance, reflectance and absorption of annealed CdS thin films with different value of thicknesses are then studied in the energy range 1.1-4.0 eV. The CdS films showed allowed direct optical band gap Eg = 2.38 eV. Films of different thicknesses have same maximum transmittance intensity at same wavelength, 590 nm but refractive index varies in the range 2.15-2.85. The photoconductivity of different thicknesses CdS films has been measured with varying light intensity level as L0.2-L1 and it has been observed that the photoconductivity is changed. The decay time constants and demarcation time (60-80 s) have been calculated by photoconductivity measurement and have same values for all different thicknesses of CdS films. The above results are useful for low cost photosensor device applications.

 

IPC Code: Int. Cl.7 H 01 L 31/0296

 

 

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 11, April 2004, pp. 137-142

 

 

Thermoluminescence response of some common brands of iodised salt

R K Gartia, B Arunkumar Sharma & Usham Ranita

 

Thermoluminescence (TL) response of ten Indian brands of iodized salt has been recorded for possible use in TL dosimetry. It has been observed that a heat treatment of one minute at 500°C reduces the complexity of the glow curve pattern. Further, in many cases heat treated samples exhibit intense peaks at higher temperature which are stable at room temperature (25°C) whereas some brands like Sungold, Tata, Ankur and Dandi inhibit such peaks. TL response of two such cases namely the integration zone 200-400°C of the glow curve of Taja and Shudh brands of iodized salt follow polynomial of degree three to beta exposure in the dose range 1 to ~ 25 Gy; indicating its potentiality in TL dosimetry.

 

IPC Code: Int. Cl.7 F 21K 2/04

 

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 11, April 2004, pp. 143-146

 

A simple method to evaluate the critical loads of cantilever columns with follower forces

K Kanaka Raju & G Venkateswara Rao

 

A simple method, based on two term Galerkin method, is presented here to evaluate the critical loads of a uniform cantilever column with follower forces. Three types of follower forces are considered. If two terms are used in the Galerkin method, a quadratic equation for the frequency is obtained and the critical loads are evaluated by making the radical of the solution of the quadratic equation zero, avoiding a frequency mapping with the applied follower force. When the radical is zero, the value of the frequency obtained is the coalescence frequency. The accuracy of results obtained from the present method is quite suitable for engineering purposes. The accuracy can further be improved if suitable admissible functions, which represent the first two modes of vibration accurately, are chosen.

 

IPC Code: Int.Cl.7 B66C 23/18