Engine Definition and 999 Threads

Good evening everyone,I had several questions regarding basic thermodynamics. After going to Paris Airshow (Le Bourget), lot's of questions came to my mind after looking at those beautiful Jet engines...I have always had a very basic understanding on these engines: a fan, a compressor (High and...

Hi guys, I have a question about engine torque control in automatic transmissions and dual clutch transmissions. I've seen cases where the engine torque is decreased on an up-shift and increased during a downshift. Why is this done?

Hi all, I have a little project on my hands and I will go into a little detail to help everyone better understand. I built a mobile boutique out of a shuttle bus for my fiancé to run her business out of. There is a large rooftop air conditioner on top of the roof for cooling and the...

Homework Statement An ideal gas with Cv = 5 2R, and γ = 1.4 starts at a volume of 1.5m3 , a pressure of 2.0×105Pa ,and a temperature of 300K. It undergoes an isobaric expansion until the volume is V , then undergoes an adiabatic expansion until the volume is 6.0m3 , and finally undergoes an...

Homework Statement The volume displacement in a car engine is 2000 cm3. During the power stroke, the mean pressure inside the cylinder is 15 bar. Compute the work performed by the engine in one revolution. Compute the engine's power assuming it runs at 3000 rpm. Homework Equations...

So I've got this crazy idea. To put it simply, to use the heat from anaerobic composting to power hot-air engine, specifically a Stirling Engine. Based solely on my own reading, the center of a closed composting heap can reach anywhere from 120-160 degrees without killing the microorganisms...

Homework Statement Consider an aircraft turbine as in the figure below. In the reference frame of the turbine, air of density ##\rho_0## comes into the turbine with speed ##U_0## through the entrance with cross sectional area ##S_0##. In the combustion zone, air is mixed with the fuel and...

Hi, I'm an automotive technician with a question on engine oil flow following a performance modification. Can you folks help me with that? Thank you, Alex

Hello everybody! I have been thinking about something for a while now. I would like to make a magnetic nozzle for a rocket engine. Basically, I would like to ionize the hot and high pressure gaz in the combustion chamber and then use a strong magnetic field to adjust the nozzle throat...

Good evening, Today's planes' need bleed air to start. Above a certain speed, igniters fire up and we inject fuel inside the combustor chamber. Why do we need to have the engine running to inject fuel (around 20%N2)? Can we simply not inject fuel with static air (i.e. when engine is not...

One big coincidence of thermodynamics is that automobiles are usually powered by an Otto cycle This cycle consists of an adiabatic compression (the cylinder compresses), isochoric compression (the fuel ignites, increasing the temperature in too short a time for the piston to move), adiabatic...

Hello everyone I have a wood chipper as shown in photos attached to this message called 'Morbark1.jpg' and 'Morbark5.jpg'. The engine on it as standard (Kohler Command CH25s 25hp) is too much hassle, time and money to fix and repair. My question is I wish to attach another engine onto the...

Ok so here it goes, I have a motorbike,and as I am a learning engineer I want to build a second engine for a few reasons, firstly I want to go faster secondly I want to do all the work myself to learn, thirdly I want to become a better engineer and want to do lots of paper work to learn and see...

Homework Statement A ship's engine supplies power of 85MW, which propels the ship of mass 5.3×106 kg across the sea at its top speed of 11##ms^{−1}##. The frictional force exerted on the ship by the sea is directly proportional to its speed. If it starts at top speed and then travels in a...

Assuming a reverse Carnot engine (Heat Pump Achieve 353K after compression and 253K after evaporation) is cascaded to Rankine turbine such that heat rejection to a steam boiler and heat is collected from a thermally isolated compartment first (used as condensation by cooling) then from ambient...

Homework Statement I am trying to calculate the efficiency of this heat engine that has two step. an adiabatic compression, followed by a linear expansion back to the original point. I keep getting an efficiency of 1, which I know can't be right... Homework Equations ##e = \frac{W}{Q_H}## The...

Homework Statement A Carnot heat engine takes 95 cycles to lift a 10 kg. mass a height of 11 m . The engine exhausts 14 J of heat per cycle to a cold reservoir at 0∘C. What is the temperature of the hot reservoir? Homework Equations η=1-(Tc/Th)=W/Qh The Attempt at a Solution I've tried...

Hello, Since childhood, I have been wondering why it is not possible to make miniature electric motors with pistons and gas container covered with a very dark (meaning high absorption coefficient over a wide spectral width) material that would translate the energy of sunlight directly into...

Hi. In my (German) physics lecture notes, I found this depiction of a Stirling engine: According to the text, it should be A: isothermal expansion B: isochoric cooling C: isothermal compression D: isochoric heating This seems correct for the PV diagram, but strange in the illustration on the...

I'm currently working on a design for a go-kart-like vehicle which involves some calculations. The engine used is a motorcycle engine and it is mounted to the main chassis via steel rods. I would like to know how the engine torque (i have an estimated value of ~45Nm) will cause stress and...

I posted this in the engineer / comp science thread, but I've had no one reply or help. I really could use some guidance and I don't know where else to post. Homework Statement I am tasked to create a PV Diagram of a Carnot Engine Cycle. I must find pressure, volume, Q, W, ΔU, and ΔS on all...

Homework Statement I am tasked to create a PV Diagram of a Carnot Engine Cycle. I must find pressure, volume, Q, W, ΔU, and ΔS on all four points. This is what has been given to me by my teacher: a to b : Isothermal b to c: Adiabatic c to d: Isothermal d to a: Adiabatic TC = 300 K TH = 1700 K...

Antimatter thrust engine would be somewhat like a chemical or nuclear thrust engine, but with the difference that the exhaust would be pure light, and the fuel would the lightest possible fuel currently known to theoretically exist. That is known, but what would it really be like, meaning like...

It has been stated in previous threads that engine inefficiencies are caused by: Pumping losses (induction and exhaust) Frictional losses (in bores, bearings, and ancilliaries) Thermal losses to exhaust, coolant (jacket, charge and oil), and surroundings Does engine vibration have an effect on...

Just out of curiosity, as I am very amateur here, in ICE could mono-crystal Alumina replace aluminum and create a better engine? Aside from the high cost to manufacture. I know MC-Alumina has a higher density than Al but is considerably stronger. This would be fantastic, I would think for a...

Hi! I am a new member to this great Forum! I am so excited to be a part of this wonderful community. Anyway, as the title suggests, I am looking for a way to calculate the pressure in each cylinder of any Four Stroke Engine at any given crank angle of Cylinder One. I have been trying creating a...

Actually I have 2 questions. 1-) How do we calculate the torque that the engine generates? t=F.d so F= The force piston exerts on crank arm. and d= length of crank arm. Can we calculate like this or is it completely different? 2-)Torque values of a car in the technical information is the...

Hey guys, I'm new to the forum and I have a question that has stumped several of the professors at my school. My idea is to use an electric motor with a solid rocket engine on a thrust stand to spin the exit cone. The concept would make use of centripetal force to increase the pressure of...

It is known that automotive engine efficiency (ie. fuel efficiency) is maximum at a specific range of medium loads. If we go higher than this range, the efficiency drops. If we go lower than these loads, the efficiency drops as well. Do we know the reasons for that? I am particularly interested...

Homework Statement Two identical bodies of constant heat capacity ##C_p## at temperatures ##T_1## and ##T_2## respectively are used as reservoirs for a heat engine. If the bodies remain at constant pressure, show that the amount of work obtainable is ##W = C_p (T_1 + T_2 − 2T_f)##, where...

Homework Statement The problem is that a Carnot contains Boiling water in the hot reservoir and ice water in the cold reservoir. Given that 0.0400kg of ice is melted in 5 minutes, what is the amount of work done by the engine. Homework Equations Qh/Qc=Th/Tc W=Qh-Qc W=(1-Tc/Th)Qs q=mHf...

So I'm starting to do some tests with nitinol (order about 5 feet of wire just to do some basic tests and get a feel for the material before I go any further). I've seen a few variations on different types of motors that are powered by nitinol and am wondering if they all have the same...

Hi Does someone know realistic numbers that i can put in this equation so i can calculate the force? Ty maximilian Popelier

I've started making my own sugar-based hobby rocket engines and I want to work on creating a de Laval nozzle for the specific fuel type and configuration I'm using. I don't have the resources to measure things like chamber pressure and exhaust temperature, so I wanted to try and develop an...

I just have read about a new kind hybrid diesel-steam engine where water has been injected inside an internal combustion engine to improve efficiency. The basic principle behind the process is that water will soak up a large section of heat generated by burning the fuel and will turn into steam...

Homework Statement A Carnot engine absorbed 1.0 kJ of heat at 300 K, and exhausted 400 J of heat at the end of the cycle. What is the temperature at the end of the cycle? Homework Equations The efficiency of a Carnot engine is given by the formula Efficiency = 1 – Qc/Qh = 1 –...

At a cost of 1 million pounds per engine there must be some very exotic materials used.

Hi guys I'm making a project about jet engine. I need to write 10 pages of the mechanical part of a jet engine. I already did it for physics. What can i talk about. I need formules en stuff in the 10 pages Ty for the help guys! Max

Homework Statement A train engine of mass ##m## is chugging its way around a circular curve of radius ##R## at a constant speed ##v##. Draw a free body/force diagram for the train engine showing all of the forces acting on it. Evaluate the total vector force acting on the engine as a function...

Homework Statement : [/B]At the beginning of the compression stroke of a two-cylinder internal combustion engine the air is at a pressure of 101.325 kPa. Compression redeuces the volume to 1/5 of its original volume, and the law of compression is given by PV^1.2 = const. If the bore and stroke...

Homework Statement http://i.imgur.com/SQ6jx94.png (sorry for the low resolution~ it's already the best i can make it~) Homework Equations U=Q+W the three variables of isobaric, isochoric, adiabatic process (can i save my effort from typing all of them out?) e=(Qh-Qc)/Qh The Attempt at a...

Homework Statement Consider an Ideal gas engine with the following cycle: i. Isobaric expansion (T1 -> Th) ii. adiabatic expansion (Th -> T2) iii. Isobaric compression (T2 -> T_L) iv. adiabatic compression (T_L -> T1) a. Find its efficiency b. When operated in two temperature, show that Carnot...

Homework Statement A toy rocket engine is securely fastened to a large puck that can glide with negligible friction over a horizontal surface, taken as the xy plane. The 4.00-kg puck has a velocity of 3.00ˆi ms at one instant. Eight seconds later, its velocity is (8.00ˆi + 10.0ˆj) ms. Assuming...

Homework Statement turning on the engine of a motorboat (v0=0), K = constant force due to the engine drag force of the water D = -cv find v(t)=? Homework Equations integration f=ma, a=dv/dt The Attempt at a Solution [/B] D+K = MA K-cv = MA (A=dv/dt) K-cv=Mdv/dt Mdv=dt(K-cv) ? i want to do...

Will a four cycle, internal combustion engine have greater thermal efficiency with a relatively cool jacket water temperature, say 160 degrees F, or a relatively hot water jacket temperature, say 190 degrees F? These specific numbers are only important in as much as they are commonly available...

I'm interested in the knowledge that was available to aircraft engineers in the period 1900-1920. specifically the thermodynamics and mechanical engineering knowledge generally available, like in how much detail were the calculations on the performance, or the cooling of engines done, how...

What is the key difference between Otto engine and Carnot engine? Other than it is reversible or not, it seems to me they are so similar. Thanks.

Homework Statement Suppose an amount of power P_{\ell} is delivered to a load by a black box with potential difference V_T across it, driving current I through a single loop. If an amount of power P_b is applied to the black box, to sustain I at V_T, then the efficiency of this black box acting...

Homework Statement Hi , I'm struggling with new paragraph about internal engines. When four-stroke internal combustion engine spins crankshaft 100 times , piston does 300 ticks. How many cilinders does engine has? Homework Equations I don't know how to create equation to calculate that , i...

The engine of a solar car I am designing(for my fictional stories but I would like a scientific point of view on this) is literally a DC circuit combined with mechanical force. First of all, there is a rechargeable battery. I would say it is about 24V fully charged. There are 2 wires coming off...