Cetane Number The cetane number of a diesel fuel is the numerical result of engine test designed to evaluate fuel ignition delay. It is defined as the whole number nearest to the value determined by calculation from percentage by volume of normal cetane (cetane No. = 100) in a blend with heptamethylnonane (cetane No. = 15) which matches the ignition quality of the test fuel when compared by this method. High cetane number fuels generally cause lower combustion noise, improved control of combustion, resulting in increased engine efficiency and power output.
Launch pressure is the pressure level of the compressed air inside the rocket and it is directly related to the thrust which is one of the major forces acting on the water rocket. The higher the launch pressure is at launch, the higher the thrust and therefore, the higher the rocket will reach; this also works in the other way. However, having very high pressure is not necessarily a good thing, it can be potentially dangerous. National physics laboratory from the UK recommends the maximum launch pressure to be no higher than 5 bars, which is approximately 5 atm. Having too much pressure can lead to the rocket exploding or other disastrous consequences, this will be further discussed about in the safety
When looking at these values it is important to think of real applications. By filling up a bottle to 57% you are creating quite a heavy rocket. This means that most of the energy used will be lifting water rather than the rocket itself. A simple estimation of optimal filling fraction can be found by dividing the Work Done by the mass of the rocket at launch: W/(rocket mass)=1/(m_o+ ρ_w*fV) (PV/(-γ+1) [(1-f)^γ-(1-f)]) Using this data we find that the ideal initial mass for our 2L bottle rocket is: m_o=m_r+f_c Vρ_w Where: m_r= mass of the empty rocket f_c= critical filling fraction of water Assuming the mass of air is negligible. So our initial mass is equal to: m_o=0.1+(0.21)(0.002)(1000) m_o=0.52 kg Plugging into Tsiolkovsky's equation: ∆v=(24.49 )ln(0.52/0.1) ∆v=40.37 m/s Given that the rocket is launching from rest we can expect the rocket to have a final velocity v_f=40.37 m/s.
Calculations • Calculate the velocity (m/s) and the Reynolds’ number for each flow rate. • Hence, find the value of friction factor from the calculated head loss for both Laminar and Turbulent flow rates. • If the flow is Laminar (i.e. Re4000), use Blasius smooth pipes. • Using the calculated values plot a graph between log (Re) and log (f).
This column – of a large surface area with glass or ceramic – provides ample contact between the vapor and liquid phases. A temperature gradient is formed because the head of the system is now further from the flask. Factors that affect the temperature gradient include the rate of heating and vapor removal from the system’s stillhead. Upon heating, the vapor of compound A rises, reaching a distance at which it no longer has enough energy to maintain its gaseous form; at this point, the molecules re-enter the liquid state. This process of rising up, condensation, and revaporization eventually results in vapor comprising 100% of substance A.
At this point, the change in pH with respect to volume was minimal since these values were far from the equivalence point, which occurred experimentally at 27.41 mL. This can also be seen on the graph as the plateau before the inflection point occured. To calculate the Ka of the acid, the following formula is
This equates to 88.45MJ of energy using the equation W=Fx. The required energy output of the catapult system must be variable. Smaller, lower mass aircraft will require less force to be exerted by the catapult to reach take-off velocity as compared to heavier aircraft with higher take-off velocities. There is a danger of over stressing the aircraft airframe if the exerted forces are too great and consequently reducing the aircraft lifespan. Steam Catapults Currently, aircraft carriers with catapult launch systems all use steam catapults.
By implementing the second law of motion the particle will accelerate or decelerate if there exists a pressure difference over the particle. The particle’s velocity will increase when it is approaching a low-pressure region and decrease its velocity at a high-pressure region. This principle can also be seen in terms of pressure. If a fluid is slowed down in the pipe the pressure will rise and vice versa. This principle is applicable to the basic way an aircraft’s wing is able to generate lift (Figure 10).
The concentration of twist-boat conformation at room temperature is very low (less than 0.1%) but at 1073 Kelvins it can reach 30%. Rapid cooling from 1073 K to 40 K will freeze in a large concentration of twist-boat conformation, which will then slowly convert to chair conformation upon heating. The half-chair conformation is a transition state with C2 symmetry generally considered to be on the pathway between chair as well as twist-boat. It involves rotating one of the dihedrals to zero such that four adjacent atoms are coplanar and the other two atoms are out of
After 40 degrees, the temperature increase became harmful to the chemical reaction. The color scale at 40 was 9.58 and at 50 the scale was 8.12. This shows at what temperature the enzyme begins to denature. Cold temperatures slow chemical reactions. At 10 degrees, the reaction occurred slower and this can be shown by the data.