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Report Title: How do High-Flying Airplanes Get Enough Oxygen for Combustion Summary There has been a need for aeronautical engineers to address the issue of speed associated with the level of altitude. Also, they have been needed to design the jets or airplanes in a way that improves their efficiency at all altitudes. However, the jets and airplanes should cruise at high altitudes where they can increase their potential to attain the maximum speed. Air density is lower at higher altitudes and this means that the jets or airplanes face less resistance as compared to when flying in the lower altitudes. As the increase of the altitude, the air becomes thin and there develops an issue with the provision of the oxygen required to carry out combustion. This report will be directed to outlining how the airplanes or jets have been designed to overcome this issue emanating from high altitudes. Introduction Airplanes and jets are supposed to fly to attain high altitudes within the first few minutes after taking off. The higher altitudes allow the airplanes and jets to be able to attain high speed which is usually required. An airplane’s potential speed also increases the higher it goes. As they ascend to these higher altitudes, the level decreases, and this could affect the functioning of the engines (Torenbeek & Wittenberg, 2009). The functioning of the engines relies on oxygen since it makes the fuel to combust and thus give the airplane the power it requires to keep on flying towards its destination. Body Airplanes or jets are supposed to fly high altitudes so that they can allow the engines to increase their efficiency. Once airplanes and jets reach high altitudes, they decrease fuel consumption because the outside air temperature decreases. Therefore, when the airplanes or jets reach these high altitudes, the airplanes are safe from birds and other low flying airplanes. At higher altitudes, airplanes are also able to fly using less fuel due to reduced resistance as air in these regions is thinner. In high altitudes, there is inadequate air. However, despite the increased efficiency of the jet engines in high altitudes, they still need oxygen for combustion. Fortunately, airplane and jet engineers have designed the engines to overcome this dilemma. Jet engines have been designed in a way that they can compress air as well to increase its pressure. Through increasing the pressure of the air, it enables higher rates of mass flow of the air enabling the engine to produce the thrust that is required to keep the airplane cruising at these higher altitudes (Torenbeek, et al., 2009). Such an achievement has been made possible by having in place compressors. In the modern airplane, there are found two to three compressor stages which make the airflow at different pressure in the various height levels. The current jets are based on the Brayton cycle. It allows for the working fluid to successfully experience isentropic compression, isobaric increase in temperature, as well as isentropic expansion. The engines that have been built following the Brayton cycle achieve the maximum possible thermodynamic efficiency as its peak cycle temperature increases (National Academies of Sciences, Engineering, and Medicine (U.S.), & Committee on Propulsion and Energy Systems to Reduce Commercial Aviation Carbon Emissions, 2016). The figure below indicates the wave rotor which is a form of technology that is used to enable constant volume combustion. It is an array of cylindrically arranged tubes in the form of a drum. Within the four-part configuration, the wave rotor is placed between the compressor exit, the inlet and the outlet of a combustion unit, and the turbine inlet. Once the drum rotates, it causes a periodical opening and closing on both sides of the tube. This movement allows the working fluid to either enter or exit the tubes. The wave rotor functions following four steps. In the initial step, the low-pressure air (which is found in the high altitudes) enters the engine compressor and into the tubes of the wave rotor. As the drum keeps on rotating, the ports of the tubes become connected with the inlet and the outlet of the combustor containing high-pressure gas. This process causes compression of the low- pressure air through shock waves. In return, the high-pressure air enters the combustor at its inlet (National Academies of Sciences, et al., 2016). Therefore, the preceding stage leaves the tube with compressed gas which is now at an elevated temperature. The next rotation ensures that the tube is connected with the turbine and the gas exits the tube to drive the turbine. Conclusion Conclusively, in high altitudes, there is not enough air for combustion. However, jets and airplanes are supposed to fly at such heights to run economically. The aeronautical engineers have been working around the clock to resolve this dilemma. Jet engines have been designed in a way that they can compress air to increase its pressure within the different altitudes. This enables the mass flow rate to increase and therefore enabling the engine to produce a thrust that is required to enable the airplane to continue flying within these high altitudes. Such an achievement has been made possible by having in place compressors. References National Academies of Sciences, Engineering, and Medicine (U.S.), & Committee on Propulsion and Energy Systems to Reduce Commercial Aviation Carbon Emissions. (2016). Commercial aircraft propulsion and energy systems research: Reducing global carbon emissions. Torenbeek, E., & Wittenberg, H. (2009). Flight physics: Essentials of aeronautical disciplines and technology, with historical notes. Dordrecht: Springer.