Analysis and Design of a Lightweight High Specific Power Two-Stroke Polygon Engine

2013 ◽  
Vol 136 (4) ◽  
Author(s):  
K. R. Anderson ◽  
A. Clark ◽  
D. Forgette ◽  
M. Devost ◽  
R. Okerson ◽  
...  
Keyword(s):  
Compression Ratio ◽  
Air Flow ◽  
Flow Analysis ◽  
Weight Ratio ◽  
System Level ◽  
Specific Power ◽  
Kinematic Modeling ◽  
Analysis And Design ◽  
Piston Speed ◽  
Piston Displacement

Current trends in engine design have pushed the state of the art regarding high power-to-weight ratio gasoline engines. Newly developed engine systems have a power-to-weight ratio near 1 hp per pound. The engine configuration presented herein makes it possible to package a large number of power producing pistons in a small volume, resulting in a power-to-weight ratio near 2 hp per pound, which has never before been realized in a production engine. The analysis and design of a lightweight two-stroke 6-sided in-plane polygon engine having a geometric compression ratio of 15.0, an actual compression ratio of 8.8, and a piston speed of 3500 ft/min are presented in this investigation. Typical results show that for a hexagonal engine with 2 in. diameter pistons and 1.25 in. stroke, a single piston displacement is 7.85 cubic in., while the total engine displacement is 47. 1 cubic in. Full power at 12,960 rpm at an air flow rate of 353 cubic feet per minute affords 0.444 cubic ft/min/hp for specific power. For an efficiency of 21%, the blower power is 168 hp. Our air-flow analysis shows that the power of the engine does not depend on the number of pistons, but rather on the volume of the gas-air mixture which passes through the engine. System level engineering of power output, kinematic modeling, air-flow modeling, efficiency, scavenging predictions, crankshaft sizing, and weight estimates are presented.

Design and Analysis of a Lightweight Polygon Engine

2013 ◽  
Author(s):  
Adam N. Clark ◽  
Kevin R. Anderson ◽  
Clifford M. Stover ◽  
Stephen L. Cunningham ◽  
Martin Stuart
Keyword(s):  
Compression Ratio ◽  
Weight Ratio ◽  
Kinematic Modeling ◽  
Gasoline Engines ◽  
Analysis And Design ◽  
Current Trends ◽  
Engine Design ◽  
Piston Speed ◽  
Engine Systems ◽  
Plane Polygon

Current trends in engine design have pushed the state-of-the-art regarding high power-to-weight ratio gasoline engines. Newly developed engine systems have a power to weight ratio near 1 hp per pound. The engine configuration presented herein makes it possible to package a large number of power producing pistons in a small volume resulting in a power to weight ratio near 2 hp per pound, which have never before been realized in a production engine. The analysis and design of a lightweight, two-stroke, 6 side, in-plane, polygon engine having a geometric compression ratio of 15.0, actual compression ratio of 8.8 and piston speed of 3500 ft/min are presented in this investigation. Power output, kinematic modeling, and weight estimates are presented.

A CFD Analysis of Telecommunication Racks, Including Effects of Air Filter Locations

2005 ◽  
Author(s):  
L. T. Yeh ◽  
B. T. F. Chung ◽  
Joseph Yeh
Keyword(s):  
Air Flow ◽  
Flow Analysis ◽  
Flow Distribution ◽  
System Level ◽  
Cfd Analysis ◽  
Failure Condition ◽  
Commercial Software ◽  
Air Filter ◽  
Level Analysis

A CFD thermal and air flow analysis is performed for a given telecommunication rack. The commercial software, Flotherm, is employed to perform the system level analysis. The analysis is made to examine the effects of the air filter locations at the upstream and downstream of the fans on the flow distribution within the system. The analysis is then extended to the case with one-fan failure condition.

scholarly journals TEG Design for Waste Heat Recovery at an Aviation Jet Engine Nozzle

2018 ◽  
Vol 8 (12) ◽  
pp. 2637 ◽  
Author(s):  
Pawel Ziolkowski ◽  
Knud Zabrocki ◽  
Eckhard Müller
Keyword(s):  
Fuel Consumption ◽  
Power Output ◽  
Waste Heat ◽  
Positive Impact ◽  
Element Model ◽  
System Level ◽  
Specific Power ◽  
Transfer Coefficients ◽  
Te Modules ◽  
Te Material

Finite element model (FEM)-based simulations are conducted for the application of a thermoelectric generator (TEG) between the hot core stream and the cool bypass flow at the nozzle of an aviation turbofan engine. This work reports the resulting requirements on the TEG design with respect to applied thermoelectric (TE) element lengths and filling factors (F) of the TE modules in order to achieve a positive effect on the specific fuel consumption. Assuming a virtual optimized TE material and varying the convective heat transfer coefficients (HTC) between the nozzle surfaces and the gas flows, this work reports the achievable power output. System-level requirement on the gravimetric power density (>100 Wkg−1) can only be met for F ≤ 21%. When extrapolating TEG coverage to the full nozzle surface, the power output reaches 1.65 kW per engine. The assessment of further potential for power generation is demonstrated by a parametric study on F, convective HTC, and materials performance. This study confirms a feasible design range for TEG installation on the aircraft nozzle with a positive impact on the fuel consumption. This application translates into a reduction of operational costs, allowing for an economically efficient TEG-installation with respect to the cost-specific power output of modern thermoelectric materials.

Indoor air flow analysis based on lattice Boltzmann methods

2002 ◽  
Vol 34 (9) ◽  
pp. 941-949 ◽  
Author(s):  
B Crouse ◽  
M Krafczyk ◽  
S Kühner ◽  
E Rank ◽  
C van Treeck
Keyword(s):  
Indoor Air ◽  
Lattice Boltzmann ◽  
Air Flow ◽  
Flow Analysis ◽  
Lattice Boltzmann Methods ◽  
Indoor Air Flow

Robust Design of Advanced Thermoelectric Conversion Systems: Probabilistic Design Impacts on Specific Power and Power Flux Optimization

2008 ◽  
Vol 1102 ◽  
Author(s):  
Terry J Hendricks ◽  
Naveen K. Karri
Keyword(s):  
System Design ◽  
Thermal Energy ◽  
Integrated System ◽  
System Level ◽  
Specific Power ◽  
Design Parameters ◽  
Probabilistic Design ◽  
Power Flux ◽  
Research Attention ◽  
System Designs

AbstractAdvanced, direct thermal energy conversion technologies are receiving increased research attention in order to recover waste thermal energy in advanced vehicles and industrial processes. Advanced thermoelectric (TE) systems necessarily require integrated system-level analyses to establish accurate optimum system designs. Past system-level design and analysis has relied on well-defined deterministic input parameters even though many critically important environmental and system design parameters in the above mentioned applications are often randomly variable, sometimes according to complex relationships, rather than discrete, well-known deterministic variables. This work describes new research and development creating techniques and capabilities for probabilistic design and analysis of advanced TE power generation systems to quantify the effects of randomly uncertain design inputs in determining more robust optimum TE system designs and expected outputs. Selected case studies involving stochastic TE .material properties demonstrate key stochastic material impacts on power, optimum TE area, specific power, and power flux in the TE design optimization process. Magnitudes and directions of these design modifications are quantified for selected TE system design analysis cases.

Measurement and Calculation of Ventilation in the Floor of the Brewery Žirovnice

2014 ◽  
Vol 1041 ◽  
pp. 321-324
Author(s):  
Jiří Jurka ◽  
Jan Škramlík
Keyword(s):  
Air Flow ◽  
Flow Analysis ◽  
Experimental Measurements ◽  
Historic Buildings ◽  
The City ◽  
Cultural Monuments

The article discusses how to test the functionality of air insulations designed for the floor ventilation in historic buildings and follows on from the previously published articles. A flow analysis is being performed on an object of the City of Zirovnice which has been registered in the list of cultural monuments and was built as a brewery in the years 1589-1592 on the site of an older medieval building. The foundations and external brickwork consist mostly of stone. This article brings new air flow readings. The aim of the article is to analyse in detail the air flow in a specific floor void with the aid of modern CFD programs and experimental measurements using the ALMEMO device.

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