scholarly journals Smooth Body

1999 ◽  
Vol 121 (10) ◽  
pp. 74-77 ◽  
Author(s):  
Paul Sharke
Keyword(s):  
Aerodynamic Drag ◽  
General Motors ◽  
Side Window ◽  
Air Inlet ◽  
Knowing That ◽  
Smooth Body ◽  
Concurrent Development ◽  
Technology Demonstration ◽  
New Generation ◽  
Cooling Air

This article describes features of a car which is General Motors' (GM) technology demonstration entry in the Partnership for a New Generation of Vehicles, the PNGV program. Compared to the EV1, the ultra-efficient two-passenger electric vehicle GM has been selling in California since 1996, the new concept car has 34 fewer counts (0.034) of aerodynamic drag. The engineers needed to establish the vehicle's architecture early, knowing that any mistakes there would be irreversible. They had to evaluate armrest positions and side-window clearance. By wearing its cooling-air intakes on the rear fenders-a benefit that comes with mounting the engine in back—the new shape borrows from sibling EV1's success with low ram air inlet. While the shape investigation was under way, an EV1 test mule aided the concurrent development of features. A full- size model of the technology demonstration shape was ready for wind-tunnel testing by June 1998.

scholarly journals Combined Gas Turbine and Diesel Generator Cooling Air Intake System

1998 ◽  
Author(s):  
Roger Yee ◽  
Alan Oswald
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Lessons Learned ◽  
Aviation Fuel ◽  
Diesel Generator ◽  
Intake System ◽  
Air Intake ◽  
New Generation ◽  
Cooling Air ◽  
The U.S

A new generation of auxiliary ships to enter the U.S. Navy (USN) fleet is the AOE-6 SUPPLY CLASS. These fast combat support ships conduct operations at sea as part of a Carrier Battle group to provide oil, aviation fuel, and ammunition to the carrier and her escorts. The SUPPLY CLASS is the first ship in the entire USN fleet to use a combined gas turbine and diesel generator cooling air intake system to cool its respective engine modules. The cooling air intake was designed this way to save on costs. As the ships in this class continued with operations and problems of insufficient supply of cooling air for the gas turbines modules started surfacing, the entire intake system required investigation and analysis. Since the gas turbines and diesel generators share a common cooling air trunk, they were competing for air. This paper will outline the tests that were performed to determine the problems, the recommended solutions, and the lessons learned from the investigations.

Investigation of the Cooling and Underbody Flow Field on a Detailed Scale Model Passenger Car: Part 2—Effect of Ground Simulation

2009 ◽  
Author(s):  
Christoffer Landstro¨m ◽  
Lasse Christoffersen ◽  
Lennart Lo¨fdahl
Keyword(s):  
Reynolds Number ◽  
Flow Field ◽  
Aerodynamic Drag ◽  
Scale Model ◽  
Experimental Investigations ◽  
Passenger Cars ◽  
Local Flow ◽  
Passenger Car ◽  
Reynolds Number Effects ◽  
Cooling Air

Future demands on passenger cars consist to a large extend of making them more energy efficient. Reducing the driving resistance by reducing the aerodynamic drag will be one important part in reducing fuel consumption. In most cases during passenger car development, early experimental investigations are performed in scale model wind tunnels. Considering that such models inevitably suffer from Reynolds number effects it is important to understand how this affects the test results. Investigations of the aerodynamics of a detailed scale model Volvo S60 have been performed in the aerodynamic wind tunnel at Chalmers University of Technology. The investigation aimed at increasing the understanding of how the flow field in scale model testing is affected by ground simulation and different cooling air flow configurations at different Reynolds numbers. A full width moving ground system was used in the experiments. Pressure taps were distributed between the cooling air inlets, the underbody and the vehicle base. An internal six component balance was used to measure global forces and moments. By combining the results from the measurements it was possible to increase the understanding of some of the local flow features. Results showed significant Reynolds number effects both with stationary ground as well as moving ground and rotating wheels. Global aerodynamic drag as well as front and rear axle lift was found to be affected.

Gas Turbine Electrical Power and Steam Generation at Allison Division of General Motors

1967 ◽  
Author(s):  
G. W. Bixler ◽  
H. J. Clifford
Keyword(s):  
Gas Turbine ◽  
Electrical Power ◽  
Aircraft Engine ◽  
High Heat ◽  
General Motors ◽  
Steam Boiler ◽  
Steam Generation ◽  
Air Inlet ◽  
High Heat Transfer ◽  
Industrial Operations

At the 1962 and 1964 ASME meetings, Allison submitted papers describing the possibilities of industrializing the T56 aircraft engine and the applications of the 501 gas turbine to industrial operations. Since 1964, Allison has been evaluating a prototype electrical power and steam generation set which has operated for approximately 20,000 hr. This paper describes the test program and the results obtained. Operating data from various engine configurations using natural gas and diesel fuel, four lubricating oils, two types of air-inlet filters, and a Harrison special high heat transfer rate exhaust gas steam boiler are also presented.

Aerodynamic Model Study of Marine Gas Turbine Exhaust Cooling

1978 ◽  
Vol 22 (02) ◽  
pp. 123-129
Author(s):  
C. J. Marquand
Keyword(s):  
Gas Turbine ◽  
Air Entrainment ◽  
Ambient Air ◽  
Royal Navy ◽  
Model Study ◽  
Plume Temperature ◽  
Gas Turbine Exhaust ◽  
New Generation ◽  
Exhaust Jet ◽  
Cooling Air

Problems such as the overheating of aerials by hot exhaust gas have been experienced by the Royal Navy on their new generation of gas turbine powered ships. Model tests indicate that the temperature trajectories from square, rectangular and clusters of circular exhausts may be correlated on the same basis as single circular exhausts, by substitution of a characteristic dimension in a simple temperature-decay equation. Plume temperature measurements show that lower temperatures can be obtained by enhancing the vortex activity in the plume, thereby causing more ambient air to be entrained, and that this can be achieved by using exhausts other than circular, where the plume drag is increased. Plume temperatures may also be reduced by introducing air entrainment into the uptake itself. Here it is important to ensure that the low-momentum entrained cooling air surrounds the hot exhaust jet as it leaves the uptake. It is then easily deflected into twin vortices in the downstream plume and these entrain ambient air. Air-entraining exhausts produce at least 20 percent lower % CTmax values in the downstream hot gas plume than more conventional exhausts.

Force Air Cooled Electronic Equipment Under Loss of Cooling Condition With Blocked Air Duct

2007 ◽  
Author(s):  
Frank Fan Wang
Keyword(s):  
Thermal Design ◽  
Electronic Equipment ◽  
Cooling Condition ◽  
Worst Case ◽  
Aerospace Applications ◽  
Air Inlet ◽  
Design Options ◽  
Forced Cooling ◽  
Cooling Air ◽  
Mean Time

There are many electronic equipments are cooled by forced cooling airs. Some equipment’s forced cooling air is supplied by air ducts, where air blower is located at a distance. In many cases, when the remote blower is out of order, the buoyancy of heated air cannot generate enough pressure to overcome the long air ducts and the blower. There is no air flow at all through the normal cooling air duct. That is called loss of cooling thermal condition. Loss of cooling condition is usually the worst case thermal challenge. In aerospace applications, most forced convection cooled electronic equipments need to meet the loss of cooling operation requirement. During loss of cooling, the electronic equipment needs to obtain cooler ambient surrounding air from a different inlet other than the supply air inlet. However, the passive cooling air inlet cannot interfere with the normal cooling situation. In normal cooling situation, forced cooling air is provided to lower the electronics temperature to a level of meeting the mean time between failure (MTBF) requirements. This paper will discuss a few trade studies of how different design approaches meet this loss of cooling air challenges; present a detailed CFD calculation of one of the design options. Many other considerations are also to be presented other than just thermal design concerns.

Utility Perspective of Selecting Air Filter for Simple-Cycle, Heavy-Duty Combustion Turbines

1993 ◽  
Vol 115 (3) ◽  
pp. 670-673
Author(s):  
J. W. Lyons ◽  
A. Morrison
Keyword(s):  
Cost Benefit ◽  
Simple Cycle ◽  
Air Filtration ◽  
Heavy Duty ◽  
Air Filters ◽  
Air Filter ◽  
Media Type ◽  
Air Inlet ◽  
Air Passage ◽  
Cooling Air

The combustion turbines evaluated for this study range in size (nominal) from 80 MW to 100 MW and operate at a compression ratio between 10 and 14. Under these conditions the compressor ingests about 500,000 to 725,000 cubic feet of air per minute for its rated output. With this volume of air, even low concentrations of contaminants can result in a significant total amount of contaminants entering the unit, which may cause compressor erosion, fouling, and foreign object damage in the compressor section and cooling air passage blockage, locking of turbine blade roots, and hot corrosion or sulfidation in the turbine section. Adequate protection against the above-mentioned degradation or damage due to poor air quality may be obtained by using properly designed air filters. An inadequate filter system or total lack of one results in a reduction in power and efficiency over the life of the unit and may significantly decrease the intervals between maintenance and thereby increase the cost of maintenance. Consideration should be given to adding an air inlet filter when or after the combustion turbine without air filter is overhauled to reduce future maintenance costs. This study investigates the need for an inlet air filtration system for simple-cycle, heavy-duty combustion turbines from a cost/benefit and operation standpoint. Options for inlet air filters include a self-cleaning pulse type filter, a surface loading cartridge filter without pulse feature, and a three-stage depth loading type media type filter. Benefits are determined by estimates of improvements in performance and effects on the combustion turbine’s longevity and maintenance.

Propulsion System Integration of Turboprop Aircraft for Basic Trainer

2000 ◽  
Author(s):  
Changduk Kong
Keyword(s):  
System Integration ◽  
Performance Test ◽  
Aerodynamic Drag ◽  
Propulsion System ◽  
Growth Potential ◽  
Propeller Wake ◽  
Air Inlet ◽  
Cross Section Area ◽  
Turboprop Engine ◽  
Exhaust Duct

The propulsion system integration of a turboprop aircraft, which has been developed for the basic trainer, was performed. The proper turboprop engine was selected among worldwide existing engines by the specific developed engine selection technique and trade-off studies such as customer’s request for operational capability (ROC), propulsion system parameters, performance analysis with engine installed effects, future growth potential, integrated logistic support (ILS), maintainability, interfaces with the airframe, etc. The chin type air inlet with the plenum chamber was designed in consideration of the inclined configuration to minimize the propeller swirl effect, the inertial separation bypass device to reduce FOD, and the super-ellipse and NACA-1 profile lip to maximize the ram recovery. The air inlet was analyzed by a higher-order source panel method considering propeller wake. The exhaust duct was designed through internal cross-section area determination to maximize the cruising power as well as external configuration to maximize the effective power, to minimize the aerodynamic drag and to minimize the cockpit contamination by the exhaust gas. The proper oil cooler for the selected turboprop engine was determined with cooling requirements and the oil cooling inlet duct with NACA configuration was designed. The test of the propulsion system including the installation performance test with the effects of the air inlet, the exhaust duct, the propeller and the nose fuselage configuration was performed in the test cell.

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