Engine Definition and 999 Threads

Homework Statement A heat engine has a carnot efficiency of 0.11. How much internal energy does this engine use in order to do 5.1 x 10^4 joules of work? How much heat does this engine give off/exhaust?Homework Equations (change in)U=Q-W W=(change in)E

Hi, I came across an engine performance graph as attached. I have basically two questions looking at that: 1.To do any engine testing we keep some parameter constant - May be throttle position or applied load (torque) or speed or power. What is kept constant for this test? 2.In the...

Homework Statement A heat engine is taking identical amounts of heat from two hot reservoirs at temperatures ##T_{H1}, T_{H2} ## doing work and then heat to a cold reservoir ##T_C ## What is the maximum efficiency of this heat engine? Homework Equations For a Carnot cyle it is ## \eta = 1 -...

What kind of engine do I need to build a "flying board"? Hi there, I'm pretty much new here and I've been making lots of research about engines, ion engines, turbines etc. But I still don't understand. I want to build a steel board, since I have the facility to work with any kind of metal...

Hello everyone this is my first steam engine made using very simple parts like cardboard, disposable syringe, straw, pen end caps and bicycle spokes. How much economical can you make your engine? Here it is costs only about Rs.10. Blowed air through mouth that's why produces lower rpm use...

Today sees a key test in the development of the SABRE engine for the Skylon Spaceplane project: http://www.bbc.co.uk/news/science-environment-17864782 What do members think of the prospect of this project? Seems to me that like all promising space ideas it would be great if it could get the...

An ideal heat engine operates with an input temperature of 327C and an exhaust temperature of 27C. If the input temperature is lowered to 227C, by how much must be the exhaust temperature be lowered to maintain the same eciency?Im using η= 1-(tc/th) that works out to 1-(300k/600k) = 0.5 then...

Carnot engine efficiency is: \eta_{work} = 1 - \frac{T_c}{T_h} Carnot refrigeration efficiency is: \eta_{cool} = \frac{ T_c }{T_h-T_c} \eta_{cool} = \frac{ 1 }{\frac{T_h}{T_c} - 1} Simple multiplication should give me the efficiency where both the engine and the refrigeration share the...

Before I Start here is a disclaimer - I am not a professional CAD or Mechanical Engineer to know much about this. Also, All information I have is from the internet and have NO practical knowledge. Here we go then. I am currently working on building a High Performance Free Flow Exhaust...

Homework Statement Hello everybody, can you help me with the following problem please. A car is going up the slope with a constant acceleration a (unknown). The friction force equals to Ffr = const. + 0,7v^2, where v is the velocity of the car. The angle of the slope is given and equals...

Physics is not my forte, but I need some answers re EMFs. I want to buy a 30-ft sailboat that has an electric engine. (I have attached a link to the exact model for reference.) Further, my intent is to live aboard. I have been planning on making my permanent bed right over the top of the...

I want to plot a cylinder pressure vs crankangle diagram for a 4 cylinder naturally aspirated diesle engine ,do I require AVL boost for this ?and how can you plot it manually?

. About a car internal combustion engine. Lets suppose the engine torque is maximum at 3500 RPMs when the engine gets also its maximum load, let's say, a 90%. This kind of data is usually shown at WOT. My question is: if the throttle is not wide open, but half open, allowing the cylinders...

With all the weight either recipricating or rotational flying around I suppose a basic conversation should be brought up when analyzing engine operation and trying to reduce power losses, rpm limiting effects.

hi. can someone help on this.. in a two wheeler automobile engine, What does a damper inside the clutch and magneto cover do... it is a rubber stripe fastened to the wall of covers..

I want to design a RC helicopter powered by a gas engine. The total mass to be lifted by the helicopter is 25 to 30 Kg. What is the engine power or engine size (in cc) required to lift the helicopter? Can someone please provide me some calculation? Regards

Homework Statement A Mechanics tries to remove an engine from a car by attaching a chain to it from a point directly overhead and then pulling sideways with a horizontal force F. If the engine has mass 180kg, what is the tension in the chain when it makes an angle of 15 degrees with vertical...

My new Civic recommends 0w 20, however it is a bit more expensive, especially if done at a dealership. Is there much difference between 0w 20 and 5w 20? I heard the only reason Honda uses 0w 20 is to meet the MPG guidelines.

"engine and control systems" vs "powertrain" I am interested in working for a person in charge of "powertrains" on cars, and I have an interview for a co-op opportunity to work with someone in charge of aviation "engine and control systems" how much would these things overlap? i guess both...

I want to use 2 radiators instead of a single radiator for cooling a maruti suzuki 800cc engine. The reason? we are participating in SUPRASAE 2012 and our space for the radiator is limited(we can't accommodate the 300*335 mm radiators but we can accommodate two radiators within 200*300 mm). Can...

Homework Statement Fifty kg of water at 0oC must be frozen into ice in a refrigerator. The room temperature is 20oC. The latent heat of fusion of water is 3.33x105 J kg-1. What is the minimum power required if the freezing is to take place in one hour? m = 50 kg Lf = 3.33x105 J kg-1...

Imagine you had a torodial tank filled with a (super)conductive fluid that was flowing around the tank in a clock-wise direction. Could the minute differences in speeds between the liquid flowing on the inside of the torus and those on the outside -slowed due to friction - create an electric...

Homework Statement A 1600 kg jet engine is fastened to the fuselage of a passenger jet by just three bolts (this is the usual practice). Assume that each bolt supports one-third of the load. (a) Calculate the force on each bolt as the plane waits in line for clearance to take off. (b) During...

Hey Guys, I'm fairly new to this forum. I would just like to know is their a way to allow for a four cylinder engine to produce for more engine gas to spin 2 turbos. As I researched on forced induction, I've found that Twin turbos on a four cylinder might be one turbo too many, though I...

Homework Statement A rocket engine has an exhaust velocity of 20,000 m/sec. The mass flow (dm/dt) rate is 1 milligram per second. a) What is the thrust produced by the engine? b) The engine propels a 200 kg space craft. What change in velocity is achievable by running the engine...

Hi As a school project, I want to construct a Stirling engine (particularly this kind : http://monsterguide.net/how-to-build-a-stirling-engine ). The execution is quite simple, but I do not fully understand the theoretical background. Can someone give me an explanation?

If a hypersonic jet (Mach 10) were to experience sudden engine failure at high altitude what would happen? Would it continue traveling forward, slowly decelerating and descending, thereby giving the pilot chance to attempt a controlled engine restart? Or would the jet experience catastrophic...

I do not really understand the reason why Carnot ideal engine needs 4 cycles: isothermal expansion, adiabatic expansion, isothermal compression, adiabatic compression. Why cannot use only 2 cycles said isobaric expansion and isobaric compression, i.e. use a heat reservoir to expand the air...

hey guys , i really need your help :) this my calculations on toyota prius model and when i calculate the IC engine power i found it equal 162.1 kw when i open Toyota Prius Specifications i found it equal only 73 kw i don't know where is the problem please help me :confused...

We have a single cylinder 500 cc petrol bike engine. It's maximum power output is 27bhp( max) and the max rpm of the engine is 5000 rpm. We need to tune the engine to MAP it accordingly. We are thinking to use a generator to convert the mechanical power into electrical power. I need help on...

How does a flywheel reduce torque fluctuations in a IC engine? Of course the more inertia you have, the less rotational speed fluctuation you get. But how does more inertia lead to less 'torque' fluctuation?

mechanical engineers i looked at wikipedia article http://en.wikipedia.org/wiki/Ford_385_engine they don't quite answer the question. the one you'd ask if you saw this engine at a machine shop or car show. what's going on with those valve covers/heads? Have A Nice Day!

Hi, I have a lawn mower engine and I need to read and adjust its rpm precisely. I am totally lost. I would like to ask how some of you would approach this problem. What I have right now is I am going to buy an Arduino circuit board controller. Then I am going to attach a tachometer onto...

Hello, My name is Jason, I am a senior high school student (new at using Physics forums), and am currently looking into alternative fuels, specifically a substitute for the popular leaded aviation fuel in use today, 100LL. 100LL contains lead to prevent engine knocking, (pre-detonation of...

Homework Statement Modern nuclear power plants have an overall efficiency of about 30%. Fossil fuel plants achieve overall efficiencies of 40%. Compare the rate of heat emission from a nuclear plant with that from a fossil fuel plant each of which produces an output power of 1000 MW...

Hi, my first post. So brief presentation, I'm an undergraduate mechanical engineer student. I hope this doesn't actually fall in homework, but it's a project that I have this semester: a steam engine car (small). I've made a bit of research and I ended up discovering the following "engine"...

Hey guys, Had this over in the mechanical engineering section but I think I might have more luck with getting an answer over here. The question is, what is happening to make the extra power when using a rich mixture in an SI engine? An air fuel ratio (AF:R) of 14.7:1 is stoichiometric for...

Hi! I have to do cartesian mesh of 3d object. I have to do this in Matlab. It will be a part of FEM programme. I've read sth about Delanuay triangulation etc, but I have to do really simple disretization sth like in http://en.wikipedia.org/wiki/Regular_grid (Example of a Cartesian grid.)...

Assuming you have a uniform expansion of gasses upon their ignition from the top most piston position to the bottom, would the force generated on the crankshaft vary at different points in the down cycle? My logic tells me that when you are in the top most part of the cycle, you would have a...

just a query about last part of a question. a mass m hangs at end of light string and is raised vertically by an engine working at a constant rate kmg.at t=o,velocity =0 x=0 and x is measured in upwards direction. now i have shown increase in total energy of the mass, when moved up a...

Does anyone know where to get an engine deck for a pt6a. I know a lot of that information is proprietary but i need one nevertheless. For those of you who don't know what an engine deck is. It gives you thrust specific fuel consumption and power lapse (thrust lapse is for a turbojet and a pt6a...

I haven't been able to find anything on this topic and maybe it's because the wear is insignificant but I would still like to know, no matter how insignificant the wear, which scenario wears the engine less. This is on a diesel engine.. On a 0F day, 3 identical diesels start up at the same...

Homework Statement A 2175 kg test plane has an engine that can deliver a maximum power of 5.28×105 watts. The pilot hits the throttle when the plane is flying at 46.8 m/s and maintains maximum power for 6.5 seconds. What is the plane's initial kinetic energy? What is the plane's change in...

Hi guys, I need to be able to estimate the thrust that a turboprop propeller produces at sea level static. Say I have an 1100 hp pt6a engine and a 80 percent efficient propeller. I have seen formulas that calculate the thrust but you need to be moving. I want to know the static (your airplane...

Hi I just wanted to know what is the mass (in kilogram) of an average car and the mass of an average engine. This is for my project and I want to know their masses to make a scaled model of a car for my experiment.

Homework Statement A borehole produces 120kg/s of high pressure water at 165°C. A powerplant is to be designed to extract heat from the water, reducing the temp to 147°C. The plant which will initially be assumed to be reversible, will reject heat at 17°C to a river. Take 147°C as the highest...

Using a series of focal reflectors, built in antenna strategically placed for proper phasing the EMF amplification system. Kinda like a space hyper engine. Possible? I can draw some blueprints I think.

Hello, I am a new user here but have found links to this site in many of my Google quests so I thought this may be the place to start a more focused search for information. I am doing a project with my son, we have created some spinning discs using magnets as a power source. I am...

We all know the constant volume combustion engine acts as a kind of internal combustion engine that is used in the car and truck extremely widely. The cycle is called Otto cycle. I also heard the constant volume combustion gas turbine engine was proposed many years ago and developed a few ones...

I will look at two different engines, which need heater, and no cooler, to operate. First one: A rocket engine, which, instead of burning fuel, simply heats up cold fuel in solid form so the heated and evaporated substance is used as a reaction mass. The nozzle of the rocket engine is in...