Optimization of diesel engine parameters using Taguchi method and design of evolution
The objective of this work is to optimize the control parameters of the direct injection (DI) single cylinder diesel engine with respect to NOx (Oxides of Nitrogen) and fuel emissions through experimental investigations and Taguchi method. A single cylinder 5.2 kW diesel engine was selected for this experiment. Five parameters such as clearance volume, valve opening pressure, nozzle-hole diameter, static injection timing and load torque were varied at four levels and the responses such as NOx emissions and fuel economy were recorded. The optimum values of the response variables could be predicted using S/N ratio and optimum combination of control parameters were specified. Results of confirmation tests showed good agreement with predicted results. Thus the relationship between the diesel engine operating parameters with NOx and b.s.f.c (brake specific fuel consumption) could be understood using Taguchi method of experimental design.
Optimizing diesel engine parameters for low emissions using Taguchi method: variation risk analysis approach—Part I
An experimental study has been carried out to simultaneously optimize several diesel engine designs and operating parameters for low exhaust emissions using Taguchi method. A single cylinder (DPF make) diesel engine equipped with a high pressure, cam driven mechanical injector has been used in this experiment. The effects of changes in engine design/operating parameters–nozzle spray holes, piston–to–head clearance, nozzle protrusion, injection control pressure, start of injection timing and swirl level on diesel engine emissions have been investigated at two engine operating conditions, i.e., 40% of maximum load and 80% of maximum load using Taguchi design of experiment methods. Emissions are quantified and optimum parameter setting has been arrived. Measurement of exhaust emissions for the optimized engine showed that CO, HC and smoke emissions are significantly lower than those obtained for the baseline engine. Taguchi method has been found to be a useful technique for the simultaneous optimization of several engine parameters and also for predicting the effect of various design parameters on diesel exhaust emissions. IPC Code: F02B
Experimental study of thermal modeling for stratospheric platform airships
R&D work on the Japanese stratospheric platform airship is discussed from the viewpoint of the thermal modeling. The work includes two experiments on the thermal characteristics of the 25m-long airship and the 35m-long PV-equipped airship model. The validity of the current thermal model was confirmed by comparing the calculated results with the measured data. The other important work is the Ground-to-Stratosphere (GTS) flight test. A 47mlong airship-shaped balloon was flown to the stratosphere. The flight simulation program into which the thermal model was integrated, was developed and applied successfully to predict the ascent behavior and the flight trajectory.