scholarly journals Multi-Response Optimization of Nanofluid-Based I. C. Engine Cooling System Using Fuzzy PIV Method

Processes ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 30 ◽  
Author(s):  
Mohd Seraj ◽  
Syed Mohd Yahya ◽  
Irfan Anjum Badruddin ◽  
Ali E. Anqi ◽  
Mohammad Asjad ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Cooling System ◽  
Heat Extraction ◽  
Inlet Temperature ◽  
Al2o3 Nanoparticles ◽  
Engine Cooling ◽  
Input Parameters ◽  
Improved Performance ◽  
Low Efficiency ◽  
Index Value

Effective cooling of the internal combustion (I. C.) engines is of utmost importance for their improved performance. Automotive heat exchangers used as radiator with low efficiency in the industry may pose a serious threat to the engines. Thus, thermal scientists and engineers are always looking for modern methods to boost the heat extraction from the engine. A novel idea of using nanofluids for engine cooling has been in the news for some time now, as they have huge potential because of better thermal properties, strength, compactness, etc. Nanofluids are expected to replace the conventional fluids such as ethylene glycol, propylene glycol, water etc. due to performance and environmental concerns. Overall performance of the engine cooling system depends on several input parameters and therefore they need to be optimised to achieve an optimum performance. This study is focussed on developing a nanofluid engine cooling system (NFECS) where Al2O3 nanoparticles mixed with ethylene glycol (EG) and water is used as nanofluid. Furthermore, it also explores the effect of four important input parameters of the NFECS i.e., nanofluid inlet temperature, engine load, nanofluid flow rate, and nanoparticle concentration on its five attributes (output responses) viz thermal conductivity of the nanofluid, heat transfer coefficient, viscosity of the nanofluid, engine pumping power required to pump the desired amount of the nanofluid, and stability of the nanofluid. Taguchi’s L18 orthogonal array is used as the design of experiment to collect experimental data. Weighting factors are determined for output responses using the Triangular fuzzy numbers (TFN) and optimal setting of the input parameters is obtained using a novel fuzzy proximity index value (FPIV) method.

scholarly journals An experimental study on cooling performance of a car radiator using Al2O3 - ethylene glycol/water nanofluid

2020 ◽  
pp. 179-179
Author(s):  
Serdar Mert ◽  
Halit Yaşar ◽  
Ufuk Durmaz ◽  
Adnan Topuz ◽  
Alper Yeter ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Cooling Power ◽  
Inlet Temperature ◽  
Al2o3 Nanoparticles ◽  
Water Mixture ◽  
Cooling Performance ◽  
Air Inlet ◽  
Vehicle Engine ◽  
Original Case ◽  
Engine Coolant

Nanofluids have high thermal conductivity and can be used as vehicle engine coolant. In this article, the effects of Al2O3 nanoparticles to an engine coolant were experimentally investigated and the results were compared with the results of the original coolant including 50% ethylene glycol and 50% water mixture. The nanofluid was prepared by adding 0.5% Al2O3 nanoparticles by volume. The inlet temperature of the coolant was held constant at 95 Celsius. The tests were carried out at the air inlet temperatures between 23.4-28.6 ?C, the air velocity between 1.7-4.3 m/s, the cooling power between 2.5-15 kW and the cooling fluid flow rates between 10-25 L/min. The results show that nanoparticles increase the cooling performance of the engine radiator. By using Al2O3 nanoparticles, cooling power of the radiator has increased up to 17.46% compared to original case.

ANALYSIS OF COMPETING VARIANTS OF AIR CONDITIONING SYSTEMS WITHOUT AIR EXTRACTION FROM ENGINES AT THE STAGE OF PASSENGER AIRCRAFT ONBOARD SYSTEMS CONCEPTUAL DESIGN

2019 ◽  
Vol 6 (3) ◽  
pp. 80-85
Author(s):  
Denis Igorevich Smagin ◽  
Konstantin Igorevich Starostin ◽  
Roman Sergeevich Savelyev ◽  
Anatoly Anatolyevich Satin ◽  
Anastasiya Romanovna Neveshkina ◽  
...  
Keyword(s):  
Conceptual Design ◽  
Air Conditioning ◽  
Research University ◽  
Cooling System ◽  
Fuel Efficiency ◽  
Air Cooling ◽  
Moscow Aviation Institute ◽  
Air Conditioning System ◽  
Low Efficiency ◽  
Air Conditioning Systems

One of the ways to achieve safety and comfort is to improve on-board air conditioning systems.The use of air cooling machine determines the air pressure high level at the point of selection from the aircraft engine compressor. Because of the aircraft operation in different modes and especially in the modes of small gas engines, deliberately high stages of selection have to be used for ensuring proper operation of the refrigeration machine in the modes of the aircraft small gas engines. Into force of this, most modes of aircraft operation have to throttle the pressure of the selected stage of selection, which, together with the low efficiency of the air cycle cooling system, makes the currently used air conditioning systems energy inefficient.A key feature of the architecture without air extraction from the main engines compressors is the use of electric drive compressors as a source of compressed air.A comparative analysis of competing variants of on-board air conditioning system without air extraction from engines for longrange aircraft projects was performed at the Moscow Aviation Institute (National Research University).The article deals with the main approaches to the decision-making process on the appearance of a promising aircraft on-board air conditioning system at the stage of its conceptual design and formulated the basic requirements for the structure of a complex criterion at different life cycle stages.The level of technical and technological risk, together with a larger installation weight, will require significant costs for development, testing, debugging and subsequent implementation, but at the same time on-board air conditioning system scheme without air extraction from the engines will achieve a significant increase in fuel efficiency at the level of the entire aircraft.

scholarly journals High Efficiency Generalized Parallel Counters for Look-Up Table Based FPGAs

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Burhan Khurshid ◽  
Roohie Naaz Mir
Keyword(s):  
Power Dissipation ◽  
High Speed ◽  
High Efficiency ◽  
Critical Path ◽  
Fir Filters ◽  
Path Delay ◽  
Look Up Table ◽  
Improved Performance ◽  
Ip Cores ◽  
Low Efficiency

Generalized parallel counters (GPCs) are used in constructing high speed compressor trees. Prior work has focused on utilizing the fast carry chain and mapping the logic onto Look-Up Tables (LUTs). This mapping is not optimal in the sense that the LUT fabric is not fully utilized. This results in low efficiency GPCs. In this work, we present a heuristic that efficiently maps the GPC logic onto the LUT fabric. We have used our heuristic on various GPCs and have achieved an improvement in efficiency ranging from 33% to 100% in most of the cases. Experimental results using Xilinx 5th-, 6th-, and 7th-generation FPGAs and Stratix IV and V devices from Altera show a considerable reduction in resources utilization and dynamic power dissipation, for almost the same critical path delay. We have also implemented GPC-based FIR filters on 7th-generation Xilinx FPGAs using our proposed heuristic and compared their performance against conventional implementations. Implementations based on our heuristic show improved performance. Comparisons are also made against filters based on integrated DSP blocks and inherent IP cores from Xilinx. The results show that the proposed heuristic provides performance that is comparable to the structures based on these specialized resources.

Characterization of an Isolated Hybrid Cooled Server With Failure Scenarios Using Warm Water Cooling

2017 ◽  
Author(s):  
Uschas Chowdhury ◽  
Manasa Sahini ◽  
Ashwin Siddarth ◽  
Dereje Agonafer ◽  
Steve Branton
Keyword(s):  
Energy Consumption ◽  
Data Centers ◽  
Cooling System ◽  
Warm Water ◽  
Alternative Methods ◽  
Inlet Temperature ◽  
Cooling Efficiency ◽  
Water Cooling ◽  
Liquid Cooling ◽  
Total Energy Consumption

Modern day data centers are operated at high power for increased power density, maintenance, and cooling which covers almost 2 percent (70 billion kilowatt-hours) of the total energy consumption in the US. IT components and cooling system occupy the major portion of this energy consumption. Although data centers are designed to perform efficiently, cooling the high-density components is still a challenge. So, alternative methods to improve the cooling efficiency has become the drive to reduce the cooling cost. As liquid cooling is more efficient for high specific heat capacity, density, and thermal conductivity, hybrid cooling can offer the advantage of liquid cooling of high heat generating components in the traditional air-cooled servers. In this experiment, a 1U server is equipped with cold plate to cool the CPUs while the rest of the components are cooled by fans. In this study, predictive fan and pump failure analysis are performed which also helps to explore the options for redundancy and to reduce the cooling cost by improving cooling efficiency. Redundancy requires the knowledge of planned and unplanned system failures. As the main heat generating components are cooled by liquid, warm water cooling can be employed to observe the effects of raised inlet conditions in a hybrid cooled server with failure scenarios. The ASHRAE guidance class W4 for liquid cooling is chosen for our experiment to operate in a range from 25°C – 45°C. The experiments are conducted separately for the pump and fan failure scenarios. Computational load of idle, 10%, 30%, 50%, 70% and 98% are applied while powering only one pump and the miniature dry cooler fans are controlled externally to maintain constant inlet temperature of the coolant. As the rest of components such as DIMMs & PCH are cooled by air, maximum utilization for memory is applied while reducing the number fans in each case for fan failure scenario. The components temperatures and power consumption are recorded in each case for performance analysis.

Superalloy Cooling System for the Composite Rim of an Inside-Out Ceramic Turbine

2017 ◽  
Author(s):  
N. Courtois ◽  
F. Ebacher ◽  
P. K. Dubois ◽  
N. Kochrad ◽  
C. Landry ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Cooling System ◽  
High Strength ◽  
Carbon Composite ◽  
Flow Rate Ratio ◽  
Small Scale ◽  
Inlet Temperature ◽  
Operating Temperatures ◽  
Critical Components ◽  
Inside Out

The use of ceramics in gas turbines potentially allows for very high cycle efficiency and power density, by increasing operating temperatures. This is especially relevant for sub-megawatt gas turbines, where the integration of complex blade cooling greatly affects machine capital cost. However, ceramics are brittle and prone to fragile, catastrophic failure, making their current use limited to static and low-stress parts. Using the inside-out ceramic turbine (ICT) configuration solves this issue by converting the centrifugal blade loading to compressive stress, by using an external high-strength carbon-polymer composite rim. This paper presents a superalloy cooling system designed to protect the composite rim and allow it to withstand operating temperatures up to 1600 K. The cooling system was designed using one-dimensional (1D) models, developed to predict flow conditions as well as the temperatures of its critical components. These models were subsequently supported with computational fluid dynamics and used to conduct a power scalability study on a single stage ICT. Results suggest that the ICT configuration should achieve a turbine inlet temperature (TIT) of 1600 K with a composite rim cooling-to-main mass flow rate ratio under 5.2% for power levels above 350 kW. A proof of concept was performed by experimental validation of a small-scale 15 kW prototype, using a commercially available bismaleimide-carbon (BMI-carbon) composite rim and Inconel® 718 nickel-based alloy. The combination of numerical and experimental results show that the ICT can operate at a TIT of 1100 K without damage to the composite rim.

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