Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

2 Archives of Thermodynamics

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Effect of evaporator surface enhancement on the performance of a two-phase closed loop thermosyphon

100%

Akhanda M. , Mahmood S.

Archives of Thermodynamics

2009

tom Vol. 30, no. 1

63-72

A two-phase closed loop thermosyphon has been designed, fabricated and tested. This thermosyphon consists of four components in its loop: an evaporator with boiling enhancement structure, vapor rising tube, condenser and condensate return tube. Tests are conducted at atmospheric pressure to assess the effects of evaporator surface geometry using three working fluids (acetone, ethanol and methanol). Four different evaporator surfaces namely smooth surface (SS), semicircular ribbed surface (SCRS), triangular ribbed surface (TRS) and saw tooth ribbed surface (STRS) have been tested in this study. Evaporator surface is heated by using an electric capsule heater which is connected to the AC power supply. Heat supply is varied using a voltage regulator which is measured by a precision ammeter and a voltmeter. Condenser section is cooled by natural circulation of air. Temperatures at different locations of the evaporator surface are measured using calibrated K type thermocouples. It is found that STRS shows the best performance among all the evaporator surfaces tested in this study and among all the working fluids used ethanol's performance is the best.

Heat transfer and friction in entry region through a square duct in turbulent flow

80%

Khan R. , Ali M. , Akhanda M.

Archives of Thermodynamics

2003

tom Vol. 24, no 3

3-15

This paper presents experimental results concerning the flow characteristics obtained in forced convection heat transfer for a turbulent flow in developing region through a smooth square duct. The duct is heated by passing alternating current. Velocity and temperature distributions across different cross-sections of the test duct are examined. The result shows that heat transfer coefficient increases by 8.73 % as Reynolds number increases up to 13.04 %. The velocity distribution attains the maximum value near the midway between the wall bisector and the adjacent wall. An empirical correlation has been developed and the result has been compared with other correlations available in the literature.