Discussion The combustion gases are mostly nitrogen (due to the 78% of N2 in air), and thus they can be treated as air with a good degree of approximation. 17-72C The Fanno line represents the states that satisfy the conservation of mass and energy equations. The Rayleigh line represents the states that satisfy the conservation of mass and momentum equations.
… As an object falls its potential energy decreases, while its kinetic energy increases. What is the system’s potential energy when its kinetic energy is equal to 34e? 17-85 Air enters a converging-diverging nozzle at a specified state. The required back pressure that produces a normal shock at the exit plane is to be determined for the specified nozzle geometry.
Discusion Note that the speed of sound is independent of pressure for ideal gases. Limited distribution permitted only to teachers and educators for course preparation. If you are a student using this Manual, you are using it without permission. 17-18C In general, no, because the Mach number also depends on the speed of sound in gas, which depends on the temperature of the gas. The Mach number remains constant only if the temperature and the velocity are constant.
Now the nozzle exit diameter is reduced by half while the nozzle inlet temperature and pressure are maintained the same. Discussion This problem could also be solved using the relations for compressible flow and normal shock functions. 17-3C Dynamic temperature is the temperature rise of a fluid during a stagnation process. what frugal billionaire eats almost every breakfast at mcdonald’s? Discussion When a gas decelerates from high speed to zero speed at a stagnation point, the temperature of the gas rises. Henry’s constant H increases with temperature, and thus the fraction of gas i in the liquid yi,liquid side decreases. Therefore, heating a liquid will drive off the dissolved gases in a liquid.
This is a control volume since mass crosses the boundary. The relationship between potential energy and kinetic energy is that potential energy can transform into kinetic energy. In other words, it changes depending on an object’s height or distance and the mass of the object. Students must note that the sum of the kinetic energy and the potential energy at any instance in the SHM remains the same as the total mechanical energy is conserved. The kinetic energy at the mean position has this value as the potential energy is zero at this point. Discussion Note that the temperature of a gas increases during a stagnation process as the kinetic energy is converted to enthalpy.
An easy way of removing the lid is to reheat the food. When the temperature rises to boiling level, the pressure rises to atmospheric value and thus the lid will come right off. 3-6C At critical point the saturated liquid and the saturated vapor states are identical.
Discussion A shock wave is a highly dissipative process, and the entropy generation is large during shock waves. Shock Waves and Expansion Waves 17-71C No, because the flow must be supersonic before a shock wave can occur. The flow in the converging section of a nozzle is always subsonic. Discussion A normal shock would occur in the supersonic section of the nozzle.
It differs from the ordinary enthalpy by the kinetic energy term. Discussion Most of the time, we mean specific enthalpy, i.e., enthalpy per unit mass, when we use the term enthalpy. 9-186 The four processes of an air-standard cycle are described. Analysis The P-v and T-s diagrams of the cycle are shown in the figures. 3-127 The pressure in an automobile tire increases during a trip while its volume remains constant. The percent increase in the absolute temperature of the air in the tire is to be determined.
Discussion No process is truly isentropic, but the increase of entropy due to sound propagation is negligibly small. 17-4C The temperature of the air rises as it approaches the nose because of the stagnation process. Discussion In the frame of reference moving with the aircraft, the air decelerates from high speed to zero at the nose , and this causes the air temperature to rise.
• The object can have zero acceleration and, simultaneously, nonzero velocity. A solid object is rotating with a constant angular acceleration. Increasing the object’s angular acceleration by a factor of two and decreasing its moment by a factor of 4 will be have what effect on the net torque on the object. If one child leans backward away from the pivot point, her side will… Satellite A has twice the mass of satellite B, and moves at the same orbital distance from Earth as satellite B. Two objects are falling at terminal velocity in the Earth’s atmosphere.