The Experts below are selected from a list of 46125 Experts worldwide ranked by ideXlab platform

L B Y Aldabbagh - One of the best experts on this subject based on the ideXlab platform.

  • single and double pass solar Air heaters with partially perforated cover and packed mesh
    Energy, 2014
    Co-Authors: Raheleh Nowzari, L B Y Aldabbagh, Fuat Egelioglu
    Abstract:

    In this study, the thermal performance of the single and double pass solar Air heaters with normal glazing and with quarter perforated cover was investigated experimentally. The solar Air collector was tested with two different perforated covers in which the holes made on one cover had the center-to-center distance of 20D (6 cm) and on the other cover it was 10D (3 cm), where D (0.3 cm) was the hole diameter. The Air Mass Flow rate was varied between 0.011 kg/s and 0.037 kg/s. The efficiency of the double pass was always greater than the single pass Air heater by 5–22.7% for the same Air Mass Flow rate. At Mass Flow rate of 0.037 kg/s, the average efficiency of single and double pass Air heaters with normal glazing were 49.98% and 53.67%, respectively. It was found that, the efficiency of the Air heater with 10D perforated cover is slightly higher than the one with 20D perforated cover for both single and counter Flow collectors. The average efficiency of single and double pass solar Air heaters with 10D perforated cover were 46.40% and 54.76%, respectively, at Mass Flow rate of 0.032 kg/s while at the same Mass Flow rate, the average efficiency of single and double pass Air heaters with normal glazing were 49.36% and 51.70%, respectively.

  • experimental performance of single and double pass solar Air heater with fins and steel wire mesh as absorber
    Applied Energy, 2010
    Co-Authors: A P Omojaro, L B Y Aldabbagh
    Abstract:

    Thermal performance of a single and double pass solar Air heater with fins attached and using a steel wire mesh as absorber plate was investigated experimentally. The effects of Air Mass Flow rate range between 0.012Â kg/s and 0.038Â kg/s on the outlet temperature and thermal efficiency was studied. The bed heights were 7Â cm and 3Â cm for the lower and upper channels respectively. Result shows that, the efficiency increase with increasing Air Mass Flow rate. For the same Flow rate, the efficiency of the double pass is found to be higher than the single pass by 7-19.4%. Maximum efficiency obtained for the single and double pass Air heater was 59.62% and 63.74% respectively for Air Mass Flow rate of 0.038Â kg/s. Moreover, the thermal efficiency further decreases by increasing the height of the first pass of the double pass solar Air heater. The temperature difference between the outlet Flow and the ambient, [Delta]T, reduces as the Air Mass Flow rate increase The result of a single or double solar Air heater using steel wire mesh arrange in layers as an absorber plate and packing material when compared with a conventional solar Air heater shows a much more substantial enhancement in the thermal efficiency.

  • experimental performance of single and double pass solar Air heater with fins and steel wire mesh as absorber
    Applied Energy, 2010
    Co-Authors: A P Omojaro, L B Y Aldabbagh
    Abstract:

    Abstract Thermal performance of a single and double pass solar Air heater with fins attached and using a steel wire mesh as absorber plate was investigated experimentally. The effects of Air Mass Flow rate range between 0.012 kg/s and 0.038 kg/s on the outlet temperature and thermal efficiency was studied. The bed heights were 7 cm and 3 cm for the lower and upper channels respectively. Result shows that, the efficiency increase with increasing Air Mass Flow rate. For the same Flow rate, the efficiency of the double pass is found to be higher than the single pass by 7–19.4%. Maximum efficiency obtained for the single and double pass Air heater was 59.62% and 63.74% respectively for Air Mass Flow rate of 0.038 kg/s. Moreover, the thermal efficiency further decreases by increasing the height of the first pass of the double pass solar Air heater. The temperature difference between the outlet Flow and the ambient, Δ T , reduces as the Air Mass Flow rate increase The result of a single or double solar Air heater using steel wire mesh arrange in layers as an absorber plate and packing material when compared with a conventional solar Air heater shows a much more substantial enhancement in the thermal efficiency.

Goker Turkakar - One of the best experts on this subject based on the ideXlab platform.

  • entropy generation analysis of a microchannel condenser for use in a vapor compression refrigeration cycle
    International Journal of Refrigeration-revue Internationale Du Froid, 2016
    Co-Authors: Goker Turkakar, Tuba Okutucuozyurt, Satish G. Kandlikar
    Abstract:

    Abstract Dimensionless entropy generation number in the microchannel condenser of a vapor compression refrigeration cycle is investigated. An Air cooled, brazed aluminum parallel Flow heat exchanger is considered as the condenser with R-134a as the refrigerant. While the effects of the fin pitch, fin height, louver angle and the Air Mass Flow rate are investigated for the Air side, the effect of the channel diameter is examined for the refrigerant side. The analysis is performed segment by segment for the superheated, two phase and subcooled regions using well-established empirical correlations. A mapping study is presented for the variation of entropy generation number with the mentioned parameters. The optimum Air Mass Flow rate interval is found to be between 0.055 and 0.1 kgs − 1 for a given fin pitch interval of 1–1.6 mm. This range is within the operating limits of Air fans in the market for this size. In this operating range, the optimal dimensions giving the minimum entropy generation numbers are presented. The entropy generation number distribution is given based on the pressure drop, heat transfer or the refrigerant state in the heat exchanger considering superheated, two phase, and subcooled regions. The entropy generation number due to pressure drop on the Air side becomes dominant after a Mass Flow rate around 0.08 kgs − 1 . Hence, an optimum Air Mass Flow rate generating the minimum entropy generation number is sought for different sizes of the condenser. The condenser length is variable in the range of 84.3–80.6 mm for the mentioned optimal Air Mass Flow rate interval. The condenser height changes depending on desired operational conditions, and it is determined to be 112.5 mm for the fixed values given in the study. The study is unique in the literature in pursuing an entropy generation number mapping study for microchannel two-phase Flow in Air cooled heat exchangers.

A P Omojaro - One of the best experts on this subject based on the ideXlab platform.

  • experimental performance of single and double pass solar Air heater with fins and steel wire mesh as absorber
    Applied Energy, 2010
    Co-Authors: A P Omojaro, L B Y Aldabbagh
    Abstract:

    Thermal performance of a single and double pass solar Air heater with fins attached and using a steel wire mesh as absorber plate was investigated experimentally. The effects of Air Mass Flow rate range between 0.012Â kg/s and 0.038Â kg/s on the outlet temperature and thermal efficiency was studied. The bed heights were 7Â cm and 3Â cm for the lower and upper channels respectively. Result shows that, the efficiency increase with increasing Air Mass Flow rate. For the same Flow rate, the efficiency of the double pass is found to be higher than the single pass by 7-19.4%. Maximum efficiency obtained for the single and double pass Air heater was 59.62% and 63.74% respectively for Air Mass Flow rate of 0.038Â kg/s. Moreover, the thermal efficiency further decreases by increasing the height of the first pass of the double pass solar Air heater. The temperature difference between the outlet Flow and the ambient, [Delta]T, reduces as the Air Mass Flow rate increase The result of a single or double solar Air heater using steel wire mesh arrange in layers as an absorber plate and packing material when compared with a conventional solar Air heater shows a much more substantial enhancement in the thermal efficiency.

  • experimental performance of single and double pass solar Air heater with fins and steel wire mesh as absorber
    Applied Energy, 2010
    Co-Authors: A P Omojaro, L B Y Aldabbagh
    Abstract:

    Abstract Thermal performance of a single and double pass solar Air heater with fins attached and using a steel wire mesh as absorber plate was investigated experimentally. The effects of Air Mass Flow rate range between 0.012 kg/s and 0.038 kg/s on the outlet temperature and thermal efficiency was studied. The bed heights were 7 cm and 3 cm for the lower and upper channels respectively. Result shows that, the efficiency increase with increasing Air Mass Flow rate. For the same Flow rate, the efficiency of the double pass is found to be higher than the single pass by 7–19.4%. Maximum efficiency obtained for the single and double pass Air heater was 59.62% and 63.74% respectively for Air Mass Flow rate of 0.038 kg/s. Moreover, the thermal efficiency further decreases by increasing the height of the first pass of the double pass solar Air heater. The temperature difference between the outlet Flow and the ambient, Δ T , reduces as the Air Mass Flow rate increase The result of a single or double solar Air heater using steel wire mesh arrange in layers as an absorber plate and packing material when compared with a conventional solar Air heater shows a much more substantial enhancement in the thermal efficiency.

Satish G. Kandlikar - One of the best experts on this subject based on the ideXlab platform.

  • entropy generation analysis of a microchannel condenser for use in a vapor compression refrigeration cycle
    International Journal of Refrigeration-revue Internationale Du Froid, 2016
    Co-Authors: Goker Turkakar, Tuba Okutucuozyurt, Satish G. Kandlikar
    Abstract:

    Abstract Dimensionless entropy generation number in the microchannel condenser of a vapor compression refrigeration cycle is investigated. An Air cooled, brazed aluminum parallel Flow heat exchanger is considered as the condenser with R-134a as the refrigerant. While the effects of the fin pitch, fin height, louver angle and the Air Mass Flow rate are investigated for the Air side, the effect of the channel diameter is examined for the refrigerant side. The analysis is performed segment by segment for the superheated, two phase and subcooled regions using well-established empirical correlations. A mapping study is presented for the variation of entropy generation number with the mentioned parameters. The optimum Air Mass Flow rate interval is found to be between 0.055 and 0.1 kgs − 1 for a given fin pitch interval of 1–1.6 mm. This range is within the operating limits of Air fans in the market for this size. In this operating range, the optimal dimensions giving the minimum entropy generation numbers are presented. The entropy generation number distribution is given based on the pressure drop, heat transfer or the refrigerant state in the heat exchanger considering superheated, two phase, and subcooled regions. The entropy generation number due to pressure drop on the Air side becomes dominant after a Mass Flow rate around 0.08 kgs − 1 . Hence, an optimum Air Mass Flow rate generating the minimum entropy generation number is sought for different sizes of the condenser. The condenser length is variable in the range of 84.3–80.6 mm for the mentioned optimal Air Mass Flow rate interval. The condenser height changes depending on desired operational conditions, and it is determined to be 112.5 mm for the fixed values given in the study. The study is unique in the literature in pursuing an entropy generation number mapping study for microchannel two-phase Flow in Air cooled heat exchangers.

V Dolz - One of the best experts on this subject based on the ideXlab platform.

  • Air Mass Flow estimation in turbocharged diesel engines from in cylinder pressure measurement
    Experimental Thermal and Fluid Science, 2010
    Co-Authors: J M Desantes, J Galindo, Carlos Guardiola, V Dolz
    Abstract:

    Air Mass Flow determination is needed for the control of current internal combustion engines. Current methods are based on specific sensors (as hot wire anemometers) or indirect estimation through manifold pressure. With the availability of cylinder pressure sensors for engine control, methods based on them can be used for replacing or complementing standard methods. Present paper uses in cylinder pressure increase during the intake stroke for inferring the trapped Air Mass. The method is validated on two different turbocharged diesel engines and compared with the standard methods.