Recent content by JohnnyS

  1. J

    Sorry here is the rest of the question. A fuel gas consists of 75% butane (C4H10), 10% propane...

    Sorry here is the rest of the question. A fuel gas consists of 75% butane (C4H10), 10% propane (C3H8) and 15% butene (C4H8) by volume. It is to be fed to the combustion chamber in 10% excess air at 25°C, where it is completely burnt to carbon dioxide and water. The flue gases produced are to be...
  2. J

    I see you have been offering assistance on the following question. I am really struggling with...

    I see you have been offering assistance on the following question. I am really struggling with this one and would appreciate any help you could offer. Calculate: The net calorific value (CV) per kmol of the fuel/air mix at 25°C? Thanks, Jon
  3. J

    Effectiveness to calculate the outlet temperatures of a heat exchanger

    Hi, I am working this same question at the moment and I have got the same answers you did for the outlet temperatures and the heat transfer rate of TC2 = 66.25°C and TH2 = 37.5°C, and the transfer rate of 129.15kW. I am now struggling with the correction factor part of the question. Following...
  4. J

    Angular Velocity Problem — a Piston and a Crank

    I have only just submitted my assignment so I don't know for sure if I have got this right but I have am pretty sure that the angualr velocity of AB is at maximum when it is perpendicular to the fully retracted / fully extended rod. So I just added the angle I calculated for the fully extended...
  5. J

    Gearbox and Flywheel Homework: Calculating Torque & Power

    Hi sponsoraw, I know this was a while ago but I am struggling with the same question. How did you get on? Do you have any helpful feedback? Thanks
  6. J

    How Do You Calculate Gear Train Efficiency Based on Load Torque?

    This is what I got for 2d) hope it helps. Efficiency = Power Out / Power In Power Out = ωT Power In = Power Out / Power Loss Power Loss = 429.4W = 410π / 3 Gear 4 ω = 400revs min-1 = (400 x 2π) / 60 = 41.89 rad s-1 = 40π / 3 Efficiency = ((ω x T) / (ω X T + power loss)) =( (40π / 3 x T)...
  7. J

    How Do You Calculate Gear Train Efficiency Based on Load Torque?

    I got my results earlier today and got a distinction. I got the first part of the gear train question wrong but the rest right based on my train. The gear train they are after is not in a straight line and some of the gears are slightly off centre. With regards to question d I will have a look...
  8. J

    Angular Velocity Problem — a Piston and a Crank

    1ii) Sorry I seem to have combined 2 answers together when typing it up. This should as you say be:- VBA = sinØ x VAO = sin45° x 1.571 = 1.1109ms-1 ωAB = VBA / lAB = 1.1109 / 0.2 ωAB = 5.55 rad s-1 With regards to the question 1iii) I am not sure as to how to type in all the mathematical...
  9. J

    Angular Velocity Problem — a Piston and a Crank

    Sorry for my delay I have been away for the weekend. Thank you for the help so far. Below I have added my calculations for question 1 and the relevant diagrams should be attached too. 1i) VAO = lOA x ωOA = 0.05 x 31.42 = 1.571ms-1 VBO = cosØ x VAO = cos45° x 1.571 VBO = 1.11ms-1 1ii) VBA =...
  10. J

    Angular Velocity Problem — a Piston and a Crank

    Homework Statement I have been set this question and I am struggling with parts b and c. I think I am nearly there but can't quite get over the line. Please could someone give me a nudge in the right direction. [/B] 1. (a) For the mechanism shown in FIGURE 1 determine for the angle θ = 45°: (i)...
  11. J

    How Do You Calculate Gear Train Efficiency Based on Load Torque?

    Sorry forgot the x 100 Efficiency = (ωT / (ωT) + (ωFr)) x 100
  12. J

    How Do You Calculate Gear Train Efficiency Based on Load Torque?

    For d) I have got as far as this: efficiency = Power out / Power in x 100 Power out = ωT Power in = Power out + Power loss Power loss = ωFr Efficiency = ωT / (ωT) + (ωFr) I am pretty sure this is not the final answer.
  13. J

    How Do You Calculate Gear Train Efficiency Based on Load Torque?

    Correction to the above calculation; Efficiency = 0.9513 x 100 Efficiency = 95.13%
  14. J

    How Do You Calculate Gear Train Efficiency Based on Load Torque?

    Honestly I used 60 and 40 as it was the first combination I tried through trial and error. I can see now that as long as the input spins at 100 revs min with a ratio of 1:4 then the final gear will always be 400 revs min-1. If I used idler gears both with 50 teeth, diameters of 100mm then from...
  15. J

    How Do You Calculate Gear Train Efficiency Based on Load Torque?

    Ok so I have answered parts a to c. 2a) The design states that the shafts must rotate in opposite directions, this means that there must be an even number of gears. If I use 2 gears they will rotate in opposite directions but each gear will have to be large in diameter to maintain the...
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