Compressed Air Car

Compressed gas sampling for microorganisms is an important part of contamination control assessment.  This paper addresses topics related to microbial assessment of compressed gases.  These include gas purity including moisture considerations, sterile filtration, compressed gas standards, microbial contamination, microbial survival, sampling and testing requirements, instrumentation, and various sampling considerations including growth medium choice and frequency, and reporting requirements.

Automobile plays a major role in transportation of passengers and goods. The engine is the power source of automobile and uses fossil fuel. However, the consumption of fossil increases emission, cost and demand. This makes the need in search of an alternate source of fuel to meet the demand. Many research are going on alternate fuels and an attempt is made to run an engine using compressed air. The modified engine works by using compressed air as fuel to produce mechanical power output without any emissions which pollutes the environment. The main aim of the project is to modify a Bajaj DTSi four stroke engine to run using compressed air. The engine operates in two strokes that is downward stroke during which the air enters and expands by doing work and the upward stroke to make the piston to reach the TDC. The air engine is tested with different pressures and load. The result showed that the increase in pressure to the inlet of the engine increases the speed and load carrying. At 10 bar pressure the engine runs at a speed of about 3000 rpm. Hence the compressed air can be integrated with conventional IC engine using the same arrangement with piston and cylinder to run a vehicle.

The environmental pollution in the metropolitan cities is increasing rapidly mostly because of the increased number of fossil fuel powered vehicles. Many alternative options are now being studied throughout the world. One of the alternative solutions can be a compressed air powered vehicle. The present study focuses on converting an SI engine into a compressed air engine. A two stroke single cylinder SI engine is converted to operate using compressed air because of its design simplicity. The cylinder head of the engine is modified by replacing the existing cam with a set of newly designed flank cam and an inlet-exhaust air passage. As the cylinder head of the engine is modified, the engine is tested for different timing of the valve opening and duration of opening. Three sets of valve timing are used to test the converted compressed air engine. The air pressure used in the present study is 7 bar which is obtained using a compressor. The design and experimental test result presented here can be used for further research and modification of the technique.

The environmental pollution in the metropolitan cities is increasing rapidly mostly because of the increased number of fossil fuel powered vehicles. Many alternative options are now being studied throughout the world. One of the alternative solutions can be a compressed air powered vehicle. Main advantage of this engine is that no hydrocarbon fuel is required which means no combustion process is taking place. In this project, an SI engine is converted into a compressed air engine. A four stroke single cylinder SI engine is converted to two stroke engine which operates using compressed air because of its design simplicity. As we converted the already existing conventional engine into an air powered one, this new technology is easy to adapt. Another benefit is that it uses air as fuel which is available abundantly in atmosphere.

The CO 2 laser cutting of three polymeric materials namely polypropylene (PP), polycarbonate (PC) and polymethyl methacrylate (PMMA) is investigated with the aim of evaluating the effect of the main input laser cutting parameters (laser power, cutting speed and compressed air pressure) on laser cutting quality of the different polymers and developing model equations relating input process parameters with the output. The output quality characteristics examined were heat affected zone (HAZ), surface roughness and dimensional accuracy. Twelve sets of tests were carried out for each of the polymer based on the central composite design. Predictive models have been developed by response surface methodology (RSM). First-order response models for HAZ and surface roughness were presented and their adequacy was tested by analysis of variance (ANOVA). It was found that the response is well modeled by a linear function of the input parameters. Response surface contours of HAZ and surface roughness were generated. Mathematical model equations have been presented that estimate HAZ and surface roughness for various input laser cutting parameters. Dimensional accuracies of laser cutting on polymers were examined by dimensional deviation of the actual value from the nominal value. From the analysis, it has been observed that PMMA has less HAZ, followed by PC and PP. For surface roughness, PMMA has better cut edge surface quality than PP and PC. The response models developed can be used for practical purposes by the manufacturing industry. However, all three polymeric materials showed similar diameter errors tendency in spite of different material properties. © 2009 Elsevier Ltd. All rights reserved.

http://ac.els-cdn.com/S0030399209001972/1-s2.0-S0030399209001972-main.pdf?_tid=41191522-1d34-11e4-b1fe-00000aacb35d&acdnat=1407307279_b9d1a06c1be9e0b532e3df78fb47e9b4 
http://www.sciencedirect.com/science/article/pii/S0030399209001972

The compressed air energy storage system has a better energy density, while the widely used hydraulic one is superior in power performance. Therefore, they are suitable for different hybrid vehicles, which require a comparative study on the performances and vehicle applicability of the broad pressure energy storage system layouts. In this paper, an integrated mathematical model of four basic pressure layouts is presented for characteristic analysis and applicability discussion. Results show that the open volume layout achieves the best power performance with the flow specific power of 13.92 MJ/m3 , thus it is suitable for heavy hybrid trucks and mobile machinery. The open mass layout achieves the best energy performance with the energy density of 124.35 MJ/m3 , which can be used in light new energy passenger vehicles. And the performance of the closed volume layout is close to the open volume layout with the flow specific power of 9.78 MJ/m3 , so it could be applied to middle and light hybrid trucks. This research provides a basis for the hybrid method of pressure energy storage system layouts for vehicles, and could be applied in the design and research of non-electric hybrid vehicles in the near future.

The CO 2 laser cutting of three polymeric materials namely polypropylene (PP), polycarbonate (PC) and polymethyl methacrylate (PMMA) is investigated with the aim of evaluating the effect of the main input laser cutting parameters (laser power, cutting speed and compressed air ...

The present study focuses the effect of four input controllable laser cutting variables on the hole taper and hole circularity in laser trepan drilling of polymeric materials. Experiments have been conducted on acrylonitrile butadiene styrene (ABS) and polymethyl methacrylate (PMMA) polymer sheets. Laser power, assist gas pressure, cutting speed and stand-off distance were selected as independent process variables. Three different holes of diameters 2 mm, 4 mm and 6 mm were drilled in these work materials of 5 mm thickness. A Taguchi L9 orthogonal array with four factors and three levels of each factor was used to plan and conduct the experiments in order to obtain required information with reduced number of experiments. The process performance was ascertained in terms of hole taper and hole circularity. Initial analysis involved in determining the effect of the four process variables on hole taper and circularity for these two polymers at three different hole diameters. From ANOVA analysis, the optimum levels of the four process variables with respect to materials and hole diameters were evaluated. As it was found that the optimum levels of four process variables were different for different hole size and materials, additional analysis was conducted to incorporate the effect of material and hole diameter on the hole taper. From the analysis, the optimum combinations were obtained at compressed air pressure of 2.0 bar, laser power of 500 W, cutting speed of 0.6 m/min, stand-off distance of 5.0 mm, hole diameter of 2.0 mm and material of PMMA. These combinations produced the minimum taper in the hole. The circularity of the hole was more at the entrance than the exit when ABS polymer was laser drilled while in PMMA, the hole was more circular at the exit than the entrance. © 2012 Elsevier Ltd. All rights reserved.

http://ac.els-cdn.com/S0143816612000723/1-s2.0-S0143816612000723-main.pdf?_tid=3a3ee6c8-1d34-11e4-b199-00000aab0f6c&acdnat=1407307268_93b66948b01c6404f407ec052584bea9 
http://www.sciencedirect.com/science/article/pii/S0143816612000723

Udara dalam industry biasanya digunakan untuk udara tekan dan instrument, dimana kedua udara ini digunakan tergantung dari karakteristik dan kegunaan masing-masing udara.  Sistem udara tekan adalah sistem udara bertekanan, dimana tekanan udara tersebut akan menghasilkan gaya yang dapat digunakan untuk menggerakkan mekanisme suatu peralatan, seperti katup (valve), torak (piston), motor udara (air motor) dan penggerak (actuator) lainnya.