The Flow behavior around a cam shaped tube in a cross Flow has been investigated experimentally using Flow Visualization and pressure distribution measurements. The range of attack angle and Reynolds number based on an equivalent circular diameter are within 0£a£360o and 2×104 Reeq>3.4×104), respectively. The pressure drag features are clarified in relation to the Flow behavior around the tube. It is found that the highest pressure drag coefficient occurs at a=90o and 270o over the whole range of Reynolds number. Results show that the pressure drag coefficient of the cam - shaped tube is lower than that of a circular tube with the same surface area for more of the attack angles.

Pultrusion is a continuous method for producing profiles with a constant cross section. Because mechanical properties of pultruded composite are related to process parameters, developing a method for Flow Visualization is essential. In this study pultrusion of thermoplastic polymers was visualized and useful data about polymer Flow and void formation during process was obtained. In this regard a straight (converging-parallel) pultrusion die with glass walls has been used for direct observation of process during pultrusion. Glass die has been heated using IR radiation for continuous heat supply and providing enough space to install Visualization equipment. Also colored pellets and fibers were used for better Visualization. Average velocity of a specific particle was measured in axial and lateral directions Vx=0.43cm/s and Vy=0.05cm/s. The average axial velocity in the entrance part of the die was measured twenty percent lower than puller speed and it gradually converged to puller speed at the end of the die. Volume of voids among the die has been reduced about 0.17 compared with first voids volume in die entrance. By using darcy law, average velocity and 7 bar measured pressure inside die, the axial permeability was calculated 5*10e-8 m2.

Operation Theatre (OT) is the most important area where precise controlled on indoor air quality is required because it is directly related to patient health and its recovery period. This work aims to study and visualize the airFlow distribution of conventional flat air diffuser ventilation system and newly designed angular air ventilation system in OT. Angular Air Distribution (AAD) system is designed in such way that, conditioned air is throw in OT with some angle so it can cover the maximum area of OT with laminar Flow and minimum installation area. The performance of angular air distribution (AAD) system with varying inlet diffuser angle, constant 0. 4m/s inlet velocity and air Flow pattern are investigated with the help of numerical simulation and experimental setup of prototype OT model. Detail experimental investigation is done on a prototype with the help of a smoke test and camera target method (CTM). Both numerical and experimental results showed a similar pattern of air distribution for the various design configurations.

Laser cladding technology has received much attention in recent years. Injection of powder by carrier gas through the nozzles plays an important role in the quality and control of the laser cladding process, so it is important to be studied. In this study, a two-phase Flow of gas-powder metal from the nozzle in a laser-cladding process is numerically simulated and compared with the results of an experimental study of the nozzle output to confirm the numerical simulation. The three-dimensional simulation was carried out steadily by Ansys CFX software. Experimental study is carried out by the Visualization of powder Flow. The results of the experimental study and the numerical simulation are in good agreement. In the next section, the effects of various parameters such as particle Flow rate, carrier gas Flow rate and shielding gas Flow rate on particle concentration are investigated. The simulation results showed that by decreasing the carrier gas Flow rate, the maximum concentration of particles increases and the particles concentration location gets closer to the nozzle outlet. Also, increasing the powder Flow rate only increases the concentration of the particles and has no effect on the other parameters of the powder Flow. The change in the shield gas Flow rate also has no effect on the powder Flow behavior.

Natural convection inside a rectangular enclosure is investigated experimentally and numerically. One of the sidewalls is heated discretely by two flush-mounted heat sources. The other sidewall is kept at a constant temperature, while the horizontal walls are unheated. Heat dissipation rates of the heat sources are equal to each other. The aspect ratio of the enclosure (AR) is 2 and the working fluid is air (Pr=0. 71). The study is focused on the validation of the two and three dimensional computations under real test conditions against experiments for various modified Rayleigh number values. Experimental study is performed for various modified Rayleigh numbers in the range of 7. 7x105 and 3. 1x106 while numerical part covers the values between 104 and 5x106. Temperature measurements and Flow Visualization studies are performed in the experimental work, and streamlines, isotherms and heatlines are presented in the numerical part of the study. From the experimental and numerical studies, it is shown that two dimensional computations reflects the general characteristics of the problem, conduction and radiation heat transfer are not negligible, surface temperatures increase with the modified Rayleigh number and heatline approach is an important tool to analyze convective heat transfer.

Background: A key aspect of Scientific collaboration increases scientific productivity. This study aimed to draw up a scientific collaboration network of the Endocrinology and Metabolism Research Institute (EMRI) at Tehran University of Medical Sciences. Methods: A Descriptive Cross-Sectional Study was conducted by the Scientometrics method. Data collection from the Scopus and Web of Science Core collection databases between 2002 until 30 October 2020. MS-Excel, HistCite, VOSviewer, and ScientoPy were used for descriptive statistics and data analysis. Results: A total of 4190 records with the affiliation of the EMRI are indexed in two international databases. All of the records received a sum of 89480 citations. The EMRI Researchers were published in 1118 journals. The annual growth rate of publication and citation of the scientific output of the EMRI was 20. 3% and 22. 7%, respectively. A total of 17662 authors from 186 countries participated in the publication. The coauthorship pattern shows. The next section of the Study was classified and visualized based on authorship (institutes and country of affiliation), keywords (co-occurrence and trend). Conclusion: Overall, these results indicate that the pattern of collaborations in the authorships' articles increases the Flow of knowledge among the institute's researchers as a result of international collaborations, interaction with leading countries, and interdisciplinary collaborations. To develop a full picture of coauthorship, additional studies will need a comprehensive picture of network cooperation to analyze the situation with other social network analysis indicators.

The wake and internal waves of a moving three dimensional (3D) airfoil body in a stratified fluid has been investigated in a large stratified tank with a finite depth using movies of shadowgraphs of the Flow fields.Typical Reynolds and Froude numbers of the Flow varied between 103 and 104, and 0.3 and 2 respectively.The Flows are generated often by towing the body in a uniformly stratified Flow, while limited cases are carried out with body stationary and the channel was in recirculating mode. For some experiments the density profile had a stepped like shape. The wake Flow is often consisted of internal waves including random and coherent ones. Distortion of density fields was also observed ahead and above the body in cases where the Froude number was subcritical. Results show that as the Froude number (Fr=U/Nh, where U is the body relative velocity, N is buoyancy frequency and h is the thickness of the body) is increased, the Flow undergoes from a subcritical narrow wake (for Fr<1) to an internal waves dominated Flow (for Fr~1) and then to a hydraulic jump with a turbulent wake with some mixing (for Fr>1). Typical wavelength of the exited internal waves is increased with Fr, as the theory predicts. The wake of the Flow for Fr>1.4 appeared to collapse and some internal waves emission from it could be observed. Usually two types of internal waves, namely random small scale and large scale, more regular waves are observed.