Experimental Investigations on Noise Attenuation of a Twin Cylinder Stationary Diesel Engine with Different Types of Mufflers

1999 ◽  
Vol 121 (3) ◽  
pp. 351-354
Author(s):  
B. K. Venkanna ◽  
Swati B. Wadawadagi

Together with atmospheric and water pollution, noise pollution is threatening human society with vehicles constituting the major source of noise. The available literature on control measures (1, 2, 3) indicates purely reactive mufflers in general are of more use for fixed speed machinery and dissipative attenuators have the ability to filler out acoustic energies over a wide range of frequencies. This paper presents cm attempt made to use a combination of these major types of mufflers fitted in the exhaust line of a four stroke, twin cylinder stationary diesel engine to attenuate exhaust noise to an acceptable level. A sound attenuation of 19 dBA has been obtained for combined reactive and dissipative (Model—M2, loosely packed with glass wool) attenuator through entire the load range without affecting the engine performance and a sound attenuation of 21 dBA has been obtained for reactive (with baffle plate. Model—M3) muffler through the entire load range with a nominal increase in BSFC at higher loads.

2021 ◽  
pp. 28-32
Author(s):  
VALERIY L. CHUMAKOV ◽  

The paper shows some ways to improve the environmental characteristics of a diesel engine using gaseous hydrocarbon fuel and operating the engine in a gas-diesel cycle mode. Some possibilities to reduce toxic components of exhaust gases in a gas-diesel engine operating on liquefi ed propane-butane mixtures have been studied. Experiments carried out in a wide range of load from 10 to 100% and speed from 1400 to 2000 rpm showed that the gas-diesel engine provides a suffi ciently high level of diesel fuel replacement with gas hydrocarbon fuel. The authors indicate some eff ective ways to reduce the toxicity of exhaust gases. The engine power should be adjusted by the simultaneous supply of fuel, gas and throttling the air charge in the intake manifold. This method enriches the fi rst combusting portions to reduce nitrogen oxides and maintains the depletion of the main charge within the fl ammability limits of the gas-air charge to reduce carbon monoxide and hydrocarbons. The authors found that when the engine operates in a gas-diesel cycle mode, the power change provides a decrease in nitrogen oxide emissions of gas-diesel fuel only due to gas supply in almost the entire load range as compared to the pure diesel. At high loads (more than 80%) stable engine operation is ensured up to 90% of diesel fuel replaced by gas. Even at 10% of diesel fuel used the concentration of nitrogen oxides decreases by at least 15…20% as compared with a diesel engine in the entire load range. However, there is an increased emission of hydrocarbons and carbon monoxide in the exhaust gases. Further experimental studies have shown that optimization of the gas diesel regulation can reduce the mass emission of nitrogen oxides contained in exhaust gases in 2…3 times and greatly reduce the emission of incomplete combustion products – carbon monoxide and hydrocarbons.


Author(s):  
Shyamsundar Rajaraman ◽  
G. K. Yashwanth ◽  
T. Rajan ◽  
R. Siva Kumaran ◽  
P. Raghu

World at present is confronted with the twin crisis of fossil fuel depletion and environmental pollution. Rapid escalation in prices and hydrocarbon resources depletion has led us to look for alternative fuels, which can satisfy ever increasing demands of energy as well as protect the environment from noxious pollutants. In this direction an attempt has been made to study a biodiesel, namely Moringa Oil Methyl Esters [MOME]. All the experiments were carried out on a 4.4 kW naturally aspirated stationary direct injection diesel engine coupled with a dynamometer to determine the engine performance and emission analysis for MOME. It was observed that there was a reduction in HC, CO and PM emissions along with a substantial increase in NOx. MOME and its blends had slightly lower thermal efficiency than diesel oil.


Author(s):  
Harsh D. Sapra ◽  
Jaswinder Singh ◽  
Chris Dijkstra ◽  
Peter De Vos ◽  
Klaas Visser

Abstract Underwater exhaust systems are employed on board ships to allow zero direct emissions to the atmosphere with the possibility of drag reduction via exhaust gas lubrication. However, underwater expulsion of exhaust gases imparts high and dynamic back pressure, which can fluctuate in amplitude and time period as a ship operates in varying sea-states depending on its geographical location and weather conditions. Therefore, this research aims to experimentally investigate the performance of a marine diesel engine against varying amplitudes and time periods of dynamic back pressure at different sea-states due to underwater exhaust systems. In this study, a turbocharged, marine diesel engine was tested at different loads along the propeller curve against dynamic back pressure waves produced by controlling an electronic butterfly valve placed in the exhaust line after the turbine outlet. Engine performance was investigated against single and multiple back pressure waves of varying amplitudes and wave periods based on real sea-state conditions and wave data. We found that the adverse effects of dynamic back pressure on engine performance were less severe than those found against static back pressure. Governor control and turbocharger dynamics play an important role in keeping the fuel penalty and thermal loading low against dynamic back pressure. Therefore, a marine engine may be able to handle much higher levels of dynamic back pressures when operating with underwater exhaust systems in higher sea-states.


Author(s):  
B. E. Knight

A simplified dimensional analysis has been made of the fuel-air mixing problem in diesel engines. The dimensionless variables describing the mixing pattern have been expressed in terms of the dimensionless variables describing the engine and fuel injection conditions by means of explicit equations with numerical values for the constants. A wide range of such equations has been derived and tables of numerical values are given as examples, together with examples of engine air motion calculations for comparison. A theoretical expression for fuel-spray penetration into a cross-wind has been compared with a few experimental results. Engine smoke and specific consumption measurements have been plotted against the appropriate dimensionless variables in two instances. In both instances the response of the engine to the variables is quite different. It is believed that the wide range of methods of engine performance data analysis outlined in this paper will make a significant contribution to progress in understanding diesel engine combustion.


2017 ◽  
Vol 11 (8) ◽  
pp. 79
Author(s):  
Jehad Ahmad Yamin

A theoretical investigation on the pressure wave action of the manifolds of a four-stroke, direct injection (hereinafter referred to as DI), water-cooled, 4-stroke, diesel engine with variable stroke length was carried out.  The study was conducted over wide range of speeds (1000 - 3000 RPM at an increment of 500 RPM) and stroke lengths (130 mm to 210 mm at an increment of 20mm). The compression ratio was kept constant by adjusting the piston bowl volume. The study showed that shorter stroke lengths created favorable pressure waves in both inlet and exhaust manifolds at lower speeds, which resulted in improved engine volumetric and thermal efficiencies. At higher speeds, the larger strokes were favorable, however, due to less time available for the suction and exhaust strokes to be executed, the efficiencies were low. Advancing valve timing was one factor that improved the engine performance with larger stroke lengths.


Author(s):  
Kuo Yang ◽  
Pingen Chen

Abstract Modern Diesel engines have become highly complex multi-input multi-output systems. Controls of modern Diesel engines to meet various requirements such as high fuel efficiency and low NOx and particulate matter (PM) emissions, remain a great challenge for automotive control community. While model-based controls have demonstrated significant potentials in achieving high Diesel engine performance. Complete and high-fidelity control-oriented Diesel engine models are much needed as the foundations of model-based control system development. In this study, a semi-physical, mean-value control-oriented model of a turbocharged Diesel engine equipped with high-pressure exhaust gas recirculation (EGR) and variable geometry turbocharger (VGT) is developed and experimentally validated. The static calibration of Diesel engine model is achieved with the least-square optimization methodology using the experimental test data from a physical Diesel engine platform. The normalized root mean square errors (NRMSEs) of the calibration results are in the range of 0.1095 to 0.2582. The cross-validation results demonstrated that the model was capable of accurately capturing the engine torque output and NOx emissions with the control inputs of EGR, VGT and Start of Injection timing (SOI) in wide-range operating conditions.


2017 ◽  
Vol 67 (4) ◽  
pp. 375 ◽  
Author(s):  
Anand Mammen Thomas ◽  
Jensen Samuel J. ◽  
Paul Pramod M. ◽  
A. Ramesh ◽  
R. Murugesan ◽  
...  

Modelling of a turbocharger is of interest to the engine designer as the work developed by the turbine can be used to drive a compressor coupled to it. This positively influences charge air density and engine power to weight ratio. Variable geometry turbocharger (VGT) additionally has a controllable nozzle ring which is normally electro-pneumatically actuated. This additional degree of freedom offers efficient matching of the effective turbine area for a wide range of engine mass flow rates. Closing of the nozzle ring (vanes tangential to rotor) result in more turbine work and deliver higher boost pressure but it also increases the back pressure on the engine induced by reduced turbine effective area. This adversely affects the net engine torque as the pumping work required increases. Hence, the optimum vane position for a given engine operating point is to be found through simulations or experimentation. A thermodynamic simulation model of a 2.2l 4 cylinder diesel engine was developed for investigation of different control strategies. Model features map based performance prediction of the VGT. Performance of the engine was simulated for steady state operation and validated with experimentation. The results of the parametric study of VGT’s vane position on the engine performance are discussed.


2018 ◽  
Vol 172 (1) ◽  
pp. 59-63
Author(s):  
Jerzy KOWALSKI

The paper presents experimental research on a 4-stroke, 3-cylinder, turbocharged AL25/30 Diesel engine. Research consisted in investigating the effect of the geometry of the fuel injectors on the exhaust gas composition from the engine. During measurements, the engine was operated with a regulator characteristic of a load range from 40 kW to 280 kW, made by electric water resistance. The engine was mechanically coupled to the electric power generator. Three observations were made for each engine load, operating with fuel injectors of varying geometry. All considered types of injectors were installed on all engine cylinders. Mentioned injectors differed in the size of the nozzle holes diameters, holes numbers and angles measured between the holes axis. Engine performance data were recorded with a sampling time of 1 s. Cylinder pressure and fuel injection pressure on the front of each injector were collected also. The composition of the exhaust gas was measured using an electrochemical analyzer. According to the results, the change of fuel nozzle geometry results in a change in fuel spraying and evaporation and consequently changes in the course of the combustion process. The effect of this is the change of the composition of the exhaust gas.


Author(s):  
Christoph Knauder ◽  
Hannes Allmaier ◽  
David E Sander ◽  
Theodor Sams

This paper presents results of experimental investigations on the friction losses of the crankshaft radial lip seals of a modern four-cylinder diesel engine for passenger car applications. A two stage strip-test has been conducted on a motored engine test bed to obtain the friction torque of the radial lip seals. For the experimental investigations with the crankshaft seals removed from the engine, a special sealing apparatus has been designed and built. A wide range of tests have been performed covering the full speed range of the engine at lubricant temperatures of 70 ℃, 90 ℃, and 110 ℃. The results show a dependency on crankshaft speed and engine media supply temperature but also revealed the presence of constant plateaus of friction torque over engine speed.


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