CHEM-E7160 Fluid flow in process units Exam 25.05.2020
All material is allowed, but only individual work. You should be able to solve all questions with a normal calculator or Excel and by using course material only. Using results from any simulation software are not accepted; you need to show how the calculation was done. If you use Excel, the worksheet is not sufficient alone for an answer, but written text is required. Written texts should be returned to a Turnitin -box, others to the assigned folders.
Maximum 5 points from each question.
You can also give additional feedback related to the whole course; in case of constructive feedback (potentially leading to improvements), additional point may be given. Please upload your feedback as a separate document.
1. Your task is to design a vertical vessel, where a vapor-liquid feed stream should be carefully separated into two outlet streams (vapor and liquid). Draw a sketch and explain important design criteria from the fluid flow point of view. Explain at least three terms relevant to this course. Max 1 page answer.
2. Derive an equation which gives blending time dependency of scale in case with geometrically similar scale-up with constant power/volume in fully turbulent conditions. What would be the blending time for mixing a solution with physical properties of water in a standard tank (liquid height / tank diameter = 1, impeller to tank diameter ratio = 1/3, Rushton turbine, four baffles), if power input is 0.1 W/kg and vessel diameter is 1 m?
3. A biker is riding at a speed of 30 km/h, with a measured power of 150 W. The rider wants to increase speed to 40 km/h
a) What is the power demand after increasing the speed, assuming all drag is due to turbulent aerodynamic resistance? Comment on the assumption.
b) If rider can improve his riding position so that CdA coefficient is reduced to 90% of the original, how much power would be needed with the higher speed?
c) How would the situation change in part a) if rolling resistance (normal friction where force is directly proportional to velocity) would be 20% of the total power consumption before the speed increase?
Bike and rider specifications are given below:
• Bike Weight: 9.5 kg
• Rider Weight: 70 kg
• Weight of the accessories (drink bottles, tools etc): 1.5 kg
• Frame: Felt Dual Aero TT / Tri UHC Performance carbon fiber, MMC w/ InsideOut construction, BB30 & horizontal dropouts w/ integrated chain tensioners, internal cable routing (electronic compatible)
• Fork: Felt Aero TT / Tri UHC Performance carbon fiber blades & dropouts, 1.125" aluminum steerer tube
• Headset: FSA IS integrated, 1.125" sealed cartridge bearing w/ aluminum 16.5mm integrated brake hanger & barrel adjuster cone spacer, 2 x 10mm + 2 x 5mm PC headset spacers & Felt top cap
• Stem: Felt SuperLite, +/-17° rise, Ø31.8mm 51cm = 80mm 54 - 56cm = 90mm 58cm = 100mm 61cm = 110mm
• Handlebar: Felt Bayonet 3 base bar w/ Felt ƒ-Bend 3-position extensions, Ø31.8mm 51 - 54cm = 390mm 56 - 61cm = 420mm
• Grips: Devox VelvetGel Tape, Felt Tri Tip Grips & Dimpled Gel Pads
• Shifters: microSHIFT TT 11-speed
• Front Derailleur: Shimano Ultegra 11-speed braze-on
• Rear Derailleur: Shimano Ultegra 11-speed short cage
• Crankset: Vision TriMax Pro TT BB30 51cm = 170mm 54 - 56cm = 172.5mm 58 - 61cm = 175mm
• Chainwheel: Vision 52/38T
• Bottom Bracket: Vision BB30
• Pedals: Garmin Vector 3
• Chain: FSA 11-speed
• Freewheel: Shimano Ultegra 11-speed, 11-25T
• Brake Levers: Aero TT / Tri
• Brakes: Felt Aero TT / Tri
• Cables: Felt Slick brake & derailleur
• Saddle: Adamo Time trial
• Seat Post: Felt DA/B Aero UHC carbon fiber, 350mm length
• Seat Post Clamp: Felt Aero Integrated DA/B
• Wheelset: Revolver Kronostok 350 6/9
• Tires: Continental GP5000, air pressure 7 bars
• Helmet: S-Works Evade
