The Effect of Fin Geometry and Manufacturing Process on Ceramic Regenerator Thermodynamic Performance

1977 ◽  
Vol 99 (4) ◽  
pp. 638-644
Author(s):  
C. A. Fucinari
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Performance Prediction ◽  
Manufacturing Process ◽  
State Of The Art ◽  
Thermodynamic Performance ◽  
Package Size ◽  
The Matrix ◽  
Simplified Analysis

The essential parameters required for accurate regenerator thermodynamic performance prediction are the basic heat transfer and pressure drop characteristics of the matrix fin configuration. The basic heat transfer and pressure drop characteristics evaluated in a “shuttle rig” of the existing “state of the art” matrix fin configurations will be presented. Based on these data, the effect of fin geometry and manufacturing process on ceramic regenerator performance will be discussed. In addition, a simplified analysis for estimating the effect of alterations in package size and/or fin parameters on regenerator performance will be presented.

scholarly journals Heat transfer and pressure drop performance of Nanofluid: A state-of- the-art review

2021 ◽  
Vol 9 ◽  
pp. 100065 ◽  
Author(s):  
Muhammad Awais ◽  
Najeeb Ullah ◽  
Javaid Ahmad ◽  
Faizan Sikandar ◽  
Mohammad Monjurul Ehsan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
State Of The Art

The Development of Performance Prediction Methods for an Automotive CO2 A/C Cycle

2011 ◽  
Vol 3 (2) ◽  
Author(s):  
Akira Kaneko ◽  
Masafumi Katsuta ◽  
Takahiro Oshiro ◽  
Sangchul Bae ◽  
Shunji Komatsu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Performance Prediction ◽  
Air Conditioning ◽  
Cooling Capacity ◽  
Refrigeration Cycle ◽  
Air Conditioning System ◽  
Lubricant Oil ◽  
C Cycle ◽  
Simulation Results

In previous research, we have been focusing on the performance of the each element heat transfer and hydraulic performance of refrigeration cycle. Experimental investigations have been repeated several times, and finally, we have substantial database including the effect of lubricant oil. Moreover, the maldistribution of two-phase in an evaporator can be also predicted from the experimental database. Under these circumstances, this study is intended to effectively put the construction of an automotive CO2 air conditioning system into practical design use through the simulation using the above-mentioned database. This paper describes the refrigeration cycle performance prediction of each element (e.g., an evaporator, a gas-cooler, and so on) by a simulation using substantial database and various available correlations proposed by us and several other researchers. In the performance prediction model of heat exchangers, local heat transfer and flow characteristics are considered and, in addition, the effects of lubricant oil on heat transfer and pressure drop are duly considered. The comparison is also made between simulation results and bench test results using a real automotive air conditioning system. Finally, the developed simulation method can predict the cooling capacity successfully within ±10% for A/C system simulation. By incorporating the lubricant oil effect, the simulation results are improved to ±5% and ±15% for the cooling capacity and pressure drop for evaporator simulation, respectively.

Development of a Microchannel Heat Exchanger for Aerospace Applications

2012 ◽  
Author(s):  
Hal Strumpf ◽  
Zia Mirza
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
State Of The Art ◽  
Design And Optimization ◽  
Microchannel Heat Exchanger ◽  
Aerospace Applications ◽  
Accurate Design ◽  
Adjustment Factors

Honeywell Aerospace has been developing microchannel heat exchangers for aerospace use. These heat exchangers offer significant reduction in volume and some reduction in weight compared to state-of-the-art aerospace heat exchangers constructed using offset plate and fin interupted surfaces. A microchannel heat exchanger was designed based on the requirements and available envelope for an aerospce liquid-to-air heat exchanger presently in service. The new micochannel heat exchanger was fabricated and a full testing campaign was undertaken to validate the design approach and generate appropriate adjustment factors for pressure drop and heat transfer. Based on this correlated model, the heat exchanger was re-sized for the required conditions. This updated design shows a significant reduction in size compared to the existing heat exchanger. In addition, Honeywell now has a validated approach enabling accurate design and optimization of microchannel heat exchangers for diverse problem conditions.

Heat Transfer and Pressure Drop Measurements on Rotating Matrix Cooling Geometries for Airfoil Trailing Edges

2015 ◽  
Author(s):  
Carlo Carcasci ◽  
Bruno Facchini ◽  
Marco Pievaroli ◽  
Lorenzo Tarchi ◽  
Alberto Ceccherini ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Gas Turbine ◽  
Rotation Number ◽  
Flow Direction ◽  
Open Area ◽  
Transfer Coefficients ◽  
Trailing Edge ◽  
Heat Transfer Coefficients ◽  
The Matrix

In the present paper the combined effects of rotation and channel orientation on heat transfer and pressure drop along two scaled up matrix geometries suitable for trailing edge cooling of gas turbine airfoils are investigated. Experimental tests were carried out under static and rotating conditions. Rotating tests were performed for two different orientations of the matrix channel with respect to the rotating plane: 0deg and 30deg. This latter configuration is representative of the exit angle of a real gas turbine blade. Test models are designed in order to replicate an internal geometry suitable for blade trailing edge cooling, with a 90deg turning flow before entering the matrix array which has an axial development. Both the investigated geometries have a cross angle of 45deg between ribs and different values of sub-channels and rib thickness: one has four sub-channels and lower rib thickness (open area 84.5%), one has six sub-channels and higher rib thickness (open area 53.5%). Both geometries have a converging angle of 11.4deg. Matrix models have been axially divided in 5 aluminum elements per side in order to evaluate the heat transfer coefficient in 5 different locations in the main flow direction. Metal temperature was measured with embedded thermocouples and thin-foil heaters were used to provide a constant heat flux during each test. Heat transfer coefficients were measured applying a steady state technique based on a regional average method and varying the sub-channel Reynolds number Res from 2000 to 10000 and the sub-channel Rotation number Ros from 0 to 0.250 in order to have both Reynolds and Rotation number similitude with the real conditions. A post-processing procedure, which takes into account the temperature gradients within the model, was developed to correctly compute average heat transfer coefficients starting from discrete temperature measurements.

Computational Study of Flow and Heat Transfer in Matrix Cooling Channels

2014 ◽  
Author(s):  
Sivasankara Reddy Ramireddy ◽  
Siddappa Pallavagere Gurusiddappa ◽  
V. Kesavan ◽  
S. Kishore Kumar
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Transfer Enhancement ◽  
Numerical Study ◽  
Computational Study ◽  
Side Wall ◽  
Transfer Enhancement ◽  
Cooling Channels ◽  
Aspect Ratios ◽  
The Matrix

A Numerical study of fluid flow, heat transfer and pressure drop in a stationary matrix cooling channel having an angle of 45 degrees for the three Reynolds numbers (24000<Re<60000) and four sub-channel aspect ratios (0.5<W/H<1.2) have been performed. This includes different shaped sub-channels such as Rectangular, U, and then two, three layered matrix combined with open and closed matrix channels. The simulation shows the development of vortices along the channel. The flow turning and impingement after hitting the side wall have significant contribution to the heat transfer enhancement. The Nusselt number and friction factor have been evaluated and compared with limited experimental results. The highest heat transfer enhancement is found at impingement region as the flow takes turn and impinges on to the wall. But slight enhancement in heat transfer is observed at turning region. The sub-channel aspect ratio has less impact on heat transfer enhancement, but more effect on pressure drop. The performance of closed matrix is relatively better than the open matrix one. The overall thermal performance (η) of the matrix having U sub-channel is nearly 10% higher than the rectangular sub-channel.

scholarly journals Thermodynamic Performance  Study on the Novel Efficient Flow Pattern Global Construction Evaporator

2021 ◽  
Author(s):  
Tianming Zhong ◽  
Haoxian Bai ◽  
LIxing Ding ◽  
Yu Xie ◽  
Shu Chen ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Pressure Drop ◽  
Flow Pattern ◽  
Minimum Entropy ◽  
Entropy Generation Number ◽  
Evaporation Heat ◽  
Thermodynamic Performance ◽  
Global Construction ◽  
Evaporation Heat Transfer

Abstract To improve in-tube evaporation heat transfer at low quality, a novel evaporator based on efficient flow pattern global construction heat transfer enhancement mechanism is built, called the efficient flow pattern global construction evaporator (EFGE). The numerical analysis and experimental study of the thermodynamic performance of the EFGE are performed. Results show that the evaporation heat transfer coefficient (HTC) of the EFGE is 0.34–1.04 times that of a common parallel flow evaporator (PFE) and the pressure drop of the EFGE is only 80–116% of that of a common PFE at quality 0.9. The theoretical nonuniformity of the evaporation HTC between low- and high-quality flow is approximately 12–67%, which 55–72% of the pressure drop. The numerical analysis results are in good agreement with the finding that the EFGE has better thermodynamic performance than the PFE in terms of friction power reduction and minimum entropy generation number.

The Development of Performance Prediction Methods for an Automotive CO2 Air Conditioning Cycle

2010 ◽  
Author(s):  
Masafumi Katsuta ◽  
Takahiro Oshiro ◽  
Akira Kaneko ◽  
Sangchul Bae ◽  
Shunji Komatsu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Data Base ◽  
Performance Prediction ◽  
Air Conditioning ◽  
Refrigeration Cycle ◽  
Air Conditioning System ◽  
Lubricant Oil ◽  
Simulation Results ◽  
Cooling Ability

In previous researches, we have been focusing on the performance of the each element heat transfer and hydraulic performance of refrigeration cycle. Experimental investigations have been repeated several times and, finally, we have substantial data base including the effect of lubricant oil. Moreover, the mal-distribution of two-phase in an evaporator can be also predicted from the experimental data base. Under these circumstances, this study is intended to effectively put the construction of an automotive CO2 air conditioning system into practical design use through the simulation using the above-mentioned data base. This paper describes the refrigeration cycle performance prediction of each element (e.g. an evaporator, a gas-cooler, and so on) by a simulation using substantial data base and various available correlations proposed by us and several other researchers. In the performance prediction model of heat exchangers, local heat transfer and flow characteristics are considered and in addition, the effects of lubricant oil on heat transfer and pressure drop are duly considered. The comparison is also made between simulation results and bench test results using a real automotive air conditioning system. Finally, the developed simulation method can predict the cooling ability successfully within ±5%. By incorporating the lubricant oil effect, the simulation results are improved to ±5% and ±15% for the cooling ability and pressure drop respectively.

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