Analyzing the peer assessment portion of the US News and World Report's college rankings, we find that administrators and faculty rate more highly universities whose football team receives a greater number of votes in either the final Associated Press or Coaches Poll. Controlling for unobserved heterogeneity, our estimates suggest that a one standard deviation increase in the number of votes received in either the Associated Press or USA Today Coaches' Football Poll is viewed as positively as a forty point increase in a school's SAT score at the 75 th percentile.

Numerical simulations were performed to determine the heat transfer coefficient of a perforated plate with square arranged cylindrical perforations. Three parameters were varied in the study: plate porosity, pitch Reynolds number and working fluid, while perforation diameter and plate thickness were constant. The Reynolds number was varied in the range from 50 to 7000, and porosity in the range from 0.1 to 0.3. As working fluids, helium, air or carbon-dioxide were set, respectively. The Nusselt number was correlated in the function of the Reynolds number, the Prandtl number, and the pitch-to-diameter ratio. The comparison with other correlations is given at the end of the paper. The difference was found to be acceptable.

The results of the experimental investigations of fluid flow and heat transfer in laboratory experimental shell-and-tube heat exchanger are presented in this paper. Shell-and-tube heat exchanger is with one pass of warm water on the shell side and two passes of cold water in tube bundle. Shell-and-tube heat exchanger is with 24×2 tubes (U-tube) in triangle layout. During each experimental run, the pressure drops and the fluid temperatures on shell side, along the shell-and-tube heat exchanger (at positions defined in advance) have been measured. The special attention was given to the investigation of the segmental baffles number influence of the shell-and-tube heat exchanger effectiveness.

No abstract

The need for compact heat exchangers has led to the development of many types of surfaces that enhance the rate of heat transfer, among them the perforated plate heat exchangers, also known as matrix heat exchangers. The perforated plate heat exchangers consist of a series of perforated plates that are separated by a series of spacers. The present study investigates the heat transfer characteristics of the package of perforated plates. Perforated plates were 2 mm thick, with holes with 2 mm in diameter and porosity of 25.6%. The package of one, two, and three perforated plates was set in the channel of the experimental chamber at which entrance was a thrust fan with the ability to control the flow rate. The fluid flow rates, the temperatures of the fluids at the inlet and outlet of the chamber and the temperature of the air between the plates, were measured at the predefined locations in the package and the experimental chamber. Based on the measurements, heat transfer coefficients for the individual plates, as well as for the packages of perforated plates were determined. In further research, an iterative analytical procedure for investigation of the heat transfer process and the overall heat transfer coefficient for the package of perforated plates were developed. Based on these analytical and experimental results, conclusions were drawn about the heat transfer in a package of perforated plates.