Mechanical Engineering

A data acquisition system is a device designed to measure various parameters. The purpose of the data acquisition system is generally the analysis of the data and the improvement in accuracy of measurements. The data acquisition system is normally electronics based, and it is made of hardware and software. The hardware part is made of sensors, signal conditioners & data acquisition card and computer. The data acquisition system increases efficiency of measurement and lowers the cost for test, through easy to integrate software like Visual Basic. With this system, Engineers can use graphical representation to meet their specific needs – very different from the conventional and traditional measurements. Additionally, data acquisition system capitalized on the ever-increasing performance of personal computers. In test, measurement, and control, the system experiences up to a 10 times increase in efficiency at a fraction of the cost, in a fraction of time, of traditional measurement system. This Dissertation work involves testing of internal combustion engine using data acquisition system . For this the data is acquired from internal combustion engine and send to computer after required conditioning. The parameters of internal combustion engine which can be measured are speed, load, temperature and vibrations . The graphical display on the computer screen can be made by using any software like Visual Basic . This is an attempt to develop a Computerized Test Rig for measurements of Speed , Load & Temperature, Vibrations using Software like Visual Basic , Hardware PCI 1050 Card with Signal Conditioning using INA128 IC and Sensors like Proximity Sensor, Load Cell and RTD .

Environmenatal factors such as climate change, gradual decrease in water resources and threatened habitants prompted the need to monitor our environment and implement better policies to protect it, thus monitoring soil pF (potential factor) values become increasingly important for environmental monitoring. The commonly available instrument(tensiometer) do not measure the range of available moisture in all soil types rather measures soil water suction. The need to measure the range of available moisture in all soil types with accuracy led to the modification of tensiometer for satisfactory laboratory results. Due to the shortcomings associated with tensiometer readings, the pressure membrane apparatus is an important instrument for optimizing irrigation and erosion prediction models.This pressure membrane with extractor has two main components:a porous plate with air entry pressure and a sealed pressure cell. The soil from which pF value was to be determined was placed in a chamber in which the pressure increased above atmospheric pressure. The side of the chamber which supports the soil consists of a pressure relief valve supported on a pressure hose. This is to ensure that the extractor chamber was not over-pressurized. The soil water potential with the corresponding mositure contents of four soil samples: A (clay soil), B(loamy soil), C (sandy soil) and D (silt) obtained from different locations were determined using pressure membrane apparatus. At a potential of 104hPa, samples A,B,C,D showed moisture content of 0.05,0.25,0.30, and 0.45cm3/cm3respectively. From the obtained results, at potentail close to zero, sandy soil is close to saturation and moisture held in the soil, primarily by capillary forces. From the laboratory analysis, moisture content decreases with high moisture cohesion.

Motor cycle accidents have been increased in the last two decades. Helmet can protect the vehicle riders from severe injuries during road accident to certain extent. To design a functional helmet, it is important to analyze the shape of the helmet and visor portion. So that the attempt has been made for design and analysis of new helmet by considering the drag pressure and anti-glare visor. The drag pressure resistance presses the helmet against the neck portion of the rider. The shape of an aerodynamic helmet can be able to reduce the drag pressure. The spherical shape and a new aerodynamic shape helmets are designed with aid of Pro-E software and the drag pressure are calculated and comparison has been made on the basis of drag pressure.

In an automobile, the wheel plays important role. Through reverse engineering process, better alloy wheel disc designs are possible by capturing the physical dimensions of the existing wheel. The objective of the present work is to recommend better material and optimal geometric shape for the wheel disc. The wheel disc is modeled in CATIA and imported to ANSYS. Analysis is done for different models. Analysis results suggest that modified model with smaller radial slots with magnesium zk60 material gives better life. The wheel disc 1.153kg lighter than that in the original design. This design is still in safe condition.

The paper presents a new approach to the classification of rolling element bearing faults by implementing Artificial Neural Network. Diagnostics of rolling element bearing faults actually represents the problem of pattern classification and recognition, where the key step is feature extraction from the vibration signal. Characterization of each recorded vibration signal is performed by a combination of signal's time-varying statistical parameters and characteristic rolling element bearing fault frequency components obtained through the frequency spectrum analysis method. The experimental data is collected for four bearings at three different speeds. The sensor is located at three different positions for each bearing. Both time domain and frequency domain signals were measured. Thus the data was three time spectrums and three frequency spectrums for each speed for a bearing. The entire data set comprised of 72 (6 x 3 x 4) data. The time domain signal was comprised of 8192 samples and extracting these features from a huge data set was difficult. To overcome this difficulty the 8192 samples were split into 32 bins each containing 256 samples. The entire process of splitting and evaluating the seven features was coded in MATLAB. From these seven features the most suitable features for explaining the intensity of the defect is discussed.

The study focused on the design of an acoustic enclosure for 12.5 kVA diesel generator with an objective to minimize the noise level to a moderately loud sound level. Factors which affect noise reduction and heat management were considered. The study revealed that the loss in transmitted sound amounted to 20dB from the initial 95dB without an enclosure, with the insertion loss being 48.6%. The analysis of the transfer of the sound wave revealed that the frequency of the incident wave was lower than the critical frequency of the enclosure, this signifies that the enclosure will not resonate during operation. The heat generated within enclosure is 19280.806kW and this will cause the maximum temperature of the cylinder head to be exceeded. To avert this, acoustic holes where designed to allow a mass flow rate of 0.57kg/sec of air to pass through the enclosure, conducting the excess heat away.

The growing concern due to environmental pollution caused by the conventional fossil fuels and the realization that they are non-renewable have led to search for more environment friendly and renewable fuels. Among various options investigated for diesel fuel, biodiesel obtained from vegetable oils has been recognized world over as one of the strong contenders for reductions in exhaust emissions. In this present experimental work is carried out the performance and emission characteristics of diesel and biodiesel (Mahua) is analyzed. The results of depicts B20 Mahua blend of biodiesel is having the better characteristics in terms of performance and emission.

In the world, day to day increases consumption of energy with increase the production rate of automobile. With the current consumption rate if it has been quoted that there will be great shortage of petroleum products in upcoming decades. For this reason research is going on alternative fuels. It is better to develop the engine which can work on bio diesel and one can add methanol in the bio diesel and use the blends of that. For this purpose, it is necessary to check the performance characteristics of the blends with the conventional diesel fuels.In this investigation, rice bran methyl ester was used in four stroke, single cylinder variable compression ratio type diesel engine. Tests were carried out at different injection pressures with various blends of rice bran methyl ester. The results proved that the use of bio diesel (produced from rice bran oil) in compression ignition engine is a viable alternative to diesel.

Nowadays, biodiesel is considered the most promising alternative fuel by the researchers due to its comparable properties with diesel fuel and also other socio-economic and environmental benefits .The investigation was conducted on a single cylinder four stroke variable compression ratio diesel engine fuelled with pure diesel, B10% (5% Methanol+ 5% Rice bran oil + 90% Diesel), 20% (5% Methanol+15% Rice bran oil +80% Diesel) and 30% (5% Methanol+25% Rice bran oil+ 70% Diesel) at different loads, at different compression ratios and at different injection pressures. The water heat loss, exhaust heat loss and unaccounted heat loss decreased with the increase of biodiesel percentage in the blends. The heat balance was in respect of useful work (HBP), heat lost through cylinder jacket water (HJW), heat lost through exhaust gasses (HGas), heat carried away by the lubricating oil and other losses (Hrad). This research work provides an in-depth analysis of the engine heat losses in different subsystems of the engine. Finally, heat energy balancing of the engine has been done by showing all energy flows in and out of the engine.

The quality of weld is depicted by weld bead geometry. In submerged arc welding (SAW) bead geometry closely related to the process parameters namely welding current, open circuit voltage, welding speed and nozzle to plate distance. So it is necessary to develop the mathematical models for bead geometry in automatic SAW machine. In the present work mathematical models are developed for bead width and bead hardness by making bead on plate (12 mm thick ASTM SA 516 Grade 60). Experiments were conducted according to the two level half factorial technique and analysis of direct and interactive effect of parameters on responses are presented with the help of Design expert software. Results were clearly illustrated that bead width increases with welding current and voltage, but decreases with welding speed and nozzle to plate distance. Bead hardness increases with Welding current, welding speed and nozzle to plate distance, but decreases with voltage.