Performance analysis of single stage libr-water absorption machine operated by waste thermal energy of internal combustion engine: Case study

2017 ◽  
Author(s):  
Hafiz Zafar Sharif ◽  
A. M. Leman ◽  
Muthuraman S. ◽  
Mohd Najib Mohd Salleh ◽  
Supaat Zakaria
Keyword(s):  
Performance Analysis ◽  
Internal Combustion Engine ◽  
Water Absorption ◽  
Thermal Energy ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Single Stage

scholarly journals The Working Principle of a Turbine “Case Study: GE Frame 9E Gas Turbine”

2019 ◽  
pp. 1-20
Author(s):  
Obolo Olupitan Emmanuel
Keyword(s):  
Internal Combustion Engine ◽  
Gas Turbine ◽  
Combustion Engine ◽  
Mechanical Energy ◽  
Internal Combustion ◽  
Reciprocating Motion ◽  
Fuel Gas ◽  
Spark Plug ◽  
Working Principle

Gas Turbine is one of the machines that use the thermodynamic principle converting fuel energy to mechanical energy. It is an internal combustion engine. Also, designed to accelerate a stream of gas, which is used to produce a reactive thrust to propel an object or to produce mechanical power that turns a load. It functions in the same way as the internal combustion engine. It sucks in air from the atmosphere, and compress it. The fuel (gas) is injected and ignited (spark plug). The gases expand doing work and finally exhausts outside. Instead of reciprocating motion, the gas turbine uses a rotary motion throughout, and that is the only difference.

Design of Turbo-Compression System for HALE UAV Propulsion System

2018 ◽  
Author(s):  
Young Seok Kang ◽  
Dong Ho Rhee ◽  
Byeung Jun Lim ◽  
Sangook Jun ◽  
Tae Choon Park ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Performance Analysis ◽  
Internal Combustion Engine ◽  
High Altitude ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Propulsion System ◽  
Flight Altitude ◽  
Compression System ◽  
Main Components

A turbo-compression system design and its performance analysis procedure for a high altitude long endurance UAV (HALE UAV), of which cruising altitude is within the stratosphere, is presented. To fly at a relatively low speed for a long time and to make engine performance less sensitive to flight altitude, a hydrogen fueled internal combustion engine was chosen for a propulsion system. To utilize an internal combustion engine as a propulsion system at a high altitude, a proper inlet pressure boost system such as a series of turbochargers is required. Hydrogen is highly reactive gas and sometimes backfiring or preignition may occur due to its low ignition energy at stoichiometric ratio. Therefore, fuel to air ratio should be reduced as low as 0.6 to avoid such phenomena. Then rarefied ambient intake air pressure should be boosted up to 1.7 bar to produce required power from the lean burn engine. To gain high pressure ratio from the turbo compression system, at least three stage serial turbocharger with proper intercooler system at each compressor exhaust is required. To analyze multi-stage turbocharger performance at the cruising altitude, an explicit one-dimensional analysis method has been established mainly by matching required power between compressors and turbines. Each compressor performances were corrected according to Reynolds number at a given flight altitude. Compressor efficiency and surge margin deteriorate as the operating altitude increases. Then compressor efficiencies were reflected as functions of flight altitude and corresponding Reynolds number. Once operating points of each turbocharger was determined, then adequate turbochargers were searched for from commercially available models based on performance analysis results. Also, adequate water to air intercoolers were chosen for the turbo-compression system to secure flexibility of placing main components inside the engine bay as well as to obtain high heat exchange efficiency of the heat exchangers. Based on the designed turbo-compression system, technical demonstration test of the turbo-compression system inside altitude environment test chamber in Korea Aerospace Research Institute is planned. Altitude condition in stratosphere is simulated mainly with two stage centrifugal compressor and additional fan will be used to fine control the flight altitude. The turbo compression system will be controlled with a single waste gate located just downstream of the engine to secure simple controllability of the turbo compression system. The test results will validate main components as well as system layout design methods and give more reliable control schedule of the turbo compressions system according to the flight altitude.

scholarly journals Vibration transmitted to operator’s back by machines with back-pack power unit: a case study on blower and spraying machines

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Roberto Deboli ◽  
Angela Calvo ◽  
Venerando Rapisarda ◽  
Christian Preti ◽  
Marco Inserillo
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Weighting Factor ◽  
The Body ◽  
Frequency Weighting ◽  
The University ◽  
Iso 2631 ◽  
Comfort Condition

To correctly evaluate the vibration transmitted to the operators, it is necessary to consider each body’s point interested by the vibratory stimulus produced by machines. All the body’s part in contact to the vibration, when a portable device with internal combustion engine is used, are: hands, back and shoulders. Some information for wholebody vibration are available in the ISO 2631-1997 standard, which otherwise refers to a seated operator. ‘C’ type standards for the vibration analysis exist for some portable machines with an internal combustion engine which is comprehensive in the machine (chainsaw, brush-cutter, blower). If the engine is not inside the machine, but it is on the operator’s back, ‘C’ type standards on vibration measurements are quite incomplete. The IMAMOTER institute of CNR, the DISAFA Department (University of Turin) and the Occupational Medicine Department of the University of Catania started some tests to verify the vibration levels transmitted to an operator working with backed engine devices. Two machines have been examined: a blower and a spraying machine. Two operative conditions have been considered during all the tests: idling and full load. Three operators have been involved and each test has been repeated three times. The spraying machine has been tested both with the empty tank and with 10 litres of water, to simulate the load to be caused by the presence of liquid inside the tank. In this work the comfort condition of ISO 2631-1 standard was considered, using the frequency weighting Wc curve with the weighting factor 0.8 for X axis (back-ventral direction) and the Wd curve for Y and Z axis (shoulder - shoulder and buttocks - head) with weighting factors 0.5 and 0.4 (respectively for Y and Z axis). Data were examined using IBM SPSS Statistics 20 software package. The statistical analysis underlined that the running condition is the main factor to condition the vibration levels transmitted to the operator’s back, while the ballast and the operators are influent when the running conditions are distinguished. Concerning medical investigation, lower back and shoulders are the main critical part of the body interested by vibration transmitted to each operator.

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