The UAV propulsion system provides the power needed to propel the aircraft for forward flight or hovering. The main types of propulsion systems are gas systems and electric systems. Both systems can be used to drive propellers or ducted fans. Each system has its advantages and disadvantages and is best suited for a specific UAV application. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay Gas propulsion systems store energy in the form of fuel and use an engine to drive propellers or other propulsion devices. There are various types of engines for UAVs, including two- or four-stroke internal combustion engines running on nitro or gasoline fuels. In general, power systems are more difficult to set up, operate and maintain than electrical systems. They are also noisier, less reliable and cannot be controlled as precisely as electrical systems. However, they can provide significantly longer flight times and can be refueled quickly. For these reasons, fuel systems are often used in UAV aircraft and helicopters that require longer flight times. In the case of autonomous UAS, the fuel propulsion system is not desirable as automatic refueling would pose a major challenge for implementation. Electric propulsion systems store energy using a battery and use electric motors to drive propellers or other propulsion devices. Electric systems are easier to use and produce less noise than gas systems. Electrical systems are more reliable and minimize the possibility of accidents due to engine shutdown or failure. The main disadvantage of electric systems is their effect on the total flight time of UAS. Although electric systems are more efficient than fuel systems, batteries can hold less energy by weight than fuel, and therefore electric systems provide significantly less flight time. Furthermore, batteries require significant charging time when empty, while fuel tanks can be refilled very quickly. Another new alternative propulsion option for UAS is fuel cells. The fuel cell is an electrochemical cell that converts the chemical energy of a fuel into electricity through an electrochemical reaction of hydrogen fuel with oxygen or another oxidizing agent. Fuel cells are different from batteries in that they require a continuous source of fuel and oxygen (usually from air) to support the chemical reaction, whereas in a battery the chemical energy comes from chemicals already present in the battery. There are some advantages to using fuel cell over battery. For example, while batteries take a long time to recharge, fuel cells can be recharged in a couple of minutes. Fuel cells can also provide much more energy and could therefore potentially extend the flight times of UAVs. However, this is a relatively new technology used in UAS and is still under development, meaning it still needs a lot of improvements before its implementation into commercial use. As this is a rapidly growing technology, it could potentially present new solutions to increase the flight performance of UAVs in the future. Please note: this is just an example. Get a custom paper from our expert writers now. Get.