Experimental study of boundary layer transition on a heated flat plate

A detailed investigation to the document momentum and thermal development of boundary layers undergoing natural transition on a heated flat plate was performed. Experimental results of both overall and conditionally sampled characteristics of laminar, transitional, and low Reynolds number turbulent boundary layers are presented. Measurements were done in a low-speed, closed-loop wind tunnel with a freestream velocity of 100 ft/s and zero pressure gradient over a range of freestream turbulence intensities from 0.4 to 6 percent. The distributions of skin friction, heat transfer rate, and Reynolds shear stress were all consistent with previously published data. Reynolds analogy factors for momentum thickness Reynolds number, Re(sub theta) less than 2300 were found to be well predicted by laminar and turbulent correlations which accounted for an unheated starting length and uniform heat flux. A small dependence of turbulence results on the freestream turbulence intensity was observed

Turbulent heat flux measurements in a transitional boundary layer

During an experimental investigation of the transitional boundary layer over a heated flat plate, an unexpected result was encountered for the turbulent heat flux (bar-v't'). This quantity, representing the correlation between the fluctuating normal velocity and the temperature, was measured to be negative near the wall under certain conditions. The result was unexpected as it implied a counter-gradient heat transfer by the turbulent fluctuations. Possible reasons for this anomalous result were further investigated. The possible causes considered for this negative bar-v't' were: (1) plausible measurement error and peculiarity of the flow facility, (2) large probe size effect, (3) 'streaky structure' in the near wall boundary layer, and (4) contributions from other terms usually assumed negligible in the energy equation including the Reynolds heat flux in the streamwise direction (bar-u't'). Even though the energy balance has remained inconclusive, none of the items (1) to (3) appear to be contributing directly to the anomaly

Critical points at infinity in charged N-body systems

We define the notion of critical points at infinity for the charged N-body problem, following the approach of Albouy (1993). We give a characterisation of such points and show how they can be found in the charged 3-body problem. The symmetry group of the N-body problem and accompanying integrals play a key role. In fact critical points at infinity are indispensible in understanding the bifurcations of the integral map. Together with the critical points at infinity in the charged 3-body problem, we present the bifurcation values.</p

Active involvement of students in co-curriculum (sports) versus generic skills

The active involvement of students in sports activities is viewed from different levels of achievement beginning with the national representation of the residential colleges, faculties, and universities in prestigious sporting events at international levels. The skills that are developed through extra-curricular activities are generic skills. The involvement of students in co-curricular activities can help to shape their generic skills, thus leading to self-promotion in the workplace. Therefore, the purpose of this research was to examine the enhancement of generic skills among engineering and technical students of UTHM who are actively involved in co-curricular activities (sports). This study will focus on identifying the factors of involvement, the level of application among students, and the perceptions of the students through their active involvement in extra-curricular activities (sports). A survey was conducted using a quantitative approach. A general questionnaire, which was designed to fulfil the objectives and to answer the research questions for this study, was distributed to 213 engineering and technical student athletes of UTHM who are actively involved in co-curricular activities (sports). It was found that the engineering and technical student athletes of UTHM agreed that their active involvement in extra-curricular activities (sports) was due to interpersonal, intrapersonal and structural factors. The results showed that out of seven generic skills, three constructs of generic skills, namely communication, teamwork and management, demonstrate a high level of application through active involvement in extra-curricular activities (sports). These findings may also help the university to focus on the development of generic skills in engineering and technical students through co-curricular activities (sports) in addition to producing athletes who are able to create a name for the university at national or international level

Growth response, water relations and K/Na ratio in wheat under sodium and calcium interactions

A study was conducted in the glass house to observe the role of K/Na ratio and moisture contents on the growth of wheat (Triticum aestivum L .cv. Lu-26) under NaCl stress. The plants were grown under hydroponic conditions at two salinity levels of 0 and 50 mM as NaCl. Calcium as CaSO4. 2H2O was applied at 3 and 6 mM to the pots of salinity. The plants were harvested after 30 days of growth. The treatments showed a highly significant (p< 0.01) effect on the growth and ionic relations. Fresh weight of shoot and root increased by 44 and 41 % respectively, with increased application of CaSO4 from 3 to 6 mM in the saline medium. Dry mass was increased by 46% at 50 mM of NaCl withthe application of 6 mM of CaSO4.2H2O. Relative water content in the root decreased with the application of CaSO4.2H2O in saline treatment as compared to non-saline treatment. The increased K/Na ratio had a pronounced effect on the increase of dry mass of shoot by 72% at 6 mM than 3 mM of CaSO4.2H2O application in the saline medium