Air Definition and 1000 Threads

Hey, I have an air tank that is at a set pressure, say 3000psi, and I have attached a regulator to the end that regulates the pressure down to 800psi. As the valve on the tank is opened the pressure and the mass in the container will decrease. If there was no regulator the mass flow rate would...

Hello, Im asking myself how to calculate the force exerted by air in a inflated unloaded tire. We now that a tire can be modeled as a spring and a damper, with vertical deflection used as spring compression and deflection velocity as damper velocity. But how about a tire with no deflection...

Homework Statement I'm doing a personal project to keep me busy for the winter. I grow Bonsai and I'm making a hospital for sick trees or recently collected ones from the wild that need to recover. I have constructed a 40x40 inch plywood box, 5/8 inch thick walls, air tight. The lid will be...

Hey, So I have a system where there is an air tank (0.2Litres @ 3000psi, 293K) and I have a convergent-divergent nozzle attached directly to it. What I want to know is an expression for how the mass flow rate varies with time as the mass in the tank decreases causing the pressure to decrease...

Is it feasible to turn the abundance of carbon in the atmosphere into graphene, given it is an allotrope of carbon and would it be worth the trouble?

This is probably a simple question but I am really struggling as to where to start. We have a tank of compressed air, Volume of tank (V1) = 0.2litres Pressure of tank (P1) = 206.8 bar Regulator Pressure (P2) = 58.6 bar I would like to find the volume of air that can pass through the regulator...

Good evening everyone, I have a pressure meter from where we determined a pressure drop of 5.5 psi (Initial pressure 45.5 psi, final pressure 40 psi). The working fluid is air. The diameter of one of the hoses that is connected to the pressure meter is 1/4". I wasn't able to take a picture of...

Halfway through my thesis on a mach 2 ramjet, and I unfortunately realize that I need 50-72 CFM to test it. The only ACs I have are 2 CFM portable pancakes. Is it possible to run say a 25 CFM AC at 50 CFM for a short period of 10-60 seconds? Is there a quantitative way to find how long the AC...

I have acquired a new compressor rated at 540 L/min @ 7 bar 150L tank I decided to test this at 23 degC, timing compression at 2 bar intervals (0-2, 2-4 etc.) I was surprised to find that it maintained 34 seconds at each interval up to 8 bar (but this could be poor experimental...

Homework Statement A ball is shot from the ground into the air. At a height of 8.8 m, the velocity is observed to be v = (7.4)i + (5.7)j in meters per second (i horizontal, j upward). To what maximum height will the ball rise? Homework Equations V^2 = Vi^2 + 2a(Δy) The Attempt at a Solution...

Homework Statement The question is: A 2 litre cooking pot (diameter: 20 cm, mass: 300g) is closed with a tight fitting lid, and contains only air. What mass of air can be maximally in the pot so that you can lift the lid, and the pot will move with the lid? Assume the surrounding pressure is...

If I have a tank of volume V, pressure P, and temperature T, what is the most effective way to determine the volume flow rate if I were to suddenly allow the air to discharge through a hose? My first thought was that I could use Boyle's Law to determine the compressed volume of air in the tank...

I want to know which kind of compressors are best for compressing very cold air. I mean as cold as they can operate in Antarctica during the winter when the temperature will reach around -50°C. In fact, I am looking for compressors that can withstand lower temperature of around -90°C. But, which...

Homework Statement Solve the differential equation ##\displaystyle Cv^2 - mg = m\frac{d^2 y}{dt^2}## Homework EquationsThe Attempt at a Solution The problem is nonlinear, so we need to use unconventional methods. Specifically, if we can express the derivative of y with respect to v, then we...

Could someone help me with getting an understanding of the equations for the power required to compress screw air please.

I don't know whether this is appropriate for this part or not, but I am now looking for turbine/machinery that can be run by compressed air to produce power/electricity. Is there any manufacturer of such a machine is available?

Hi All, Quick question about the flow velocity in an air ringmain piping system. does the flow velocity in the ringmain pipe decrease every time it passes an outlet?

Hi, I am working on a product design which would be used sub sea. It is designed to lift a small load off the sea bed. I have not worked out the exact details yet but the following should be a good start: Load 30Kg Depth 30m I plan on using an air bag of some description - the bag needs to...

I'm trying to calculate the battery requirements for an experimental home built air compressor. I understand that electromagnetic air compressors operate using attraction and repulsion forces created by electromagnets using the basic magnetic principle that like poles of two magnets repel and...

Anyone have any backup ideas/plans for me because it appears that my Air Force career goal isn't working out... as in they might not even bother to send me to MEPs because of an issue. Thanks!

Hey guys! So the below question might sound like a homework question but in reality it is an oversimplified explanation of what I'm trying to measure Let's say we have a perfect machine that pushes out 600CFM into a box. On the other end of the box is another small machine that only consumes...

Suppose, there are two cylinders of compressed gas, say air. Both are at same temperature and pressure and the amount too is same. Now, contents of both are released but in a different way. One has been released directly and the other has been released through compressed air turbine having a...

I'm at an internship and I saw a container labeled ultrasonic gel, which is used to prevent air from coming between a scanner and the human body. This is necessary because apparently ultrasound doesn't travel through air well. Why is this? (don't say because the density is low, because I will...

I was wondering if it is possible to image the motion of individual air molecules? What I am picturing is using a laser to illuminate a volume of air, and using scattered light to measure the velocity of individual air molecules through the doppler shift of the scattered light. It seems that...

If a hot air balloon cools enough to start descending, does it keep accelerating until it hits the ground? Assume that the air inside does not cool off anymore, and pretend that the air pressure stays the same at all altitudes. I tried testing it by dropping a coin into a pool. It didn't seem...

what is the direction of velocity observed by fish when man flying from air to water?

I want to calculate the force-displacement curve for a damper that would have hydraulic oil with an air bubble in it, so very similar to an air spring with a limited amount of volume. I came up with the following solution: F(x)=Po*A((Vo/Vo-A*x)-1) where F would be the external force applied...

Hello, assume I have an air condition unit which is not very strong and thus always runs at full power. If I let water evaporate in the room without adding heat (e.g. by hanging lots of wet towels), will this improve the heat removal by the aircon unit and thus lower the room temperature, or...

HELLO PEOPLE! Sorry for the enthusiasm but, this is my first post. I am in the process of getting my masters in material science and engineering and I liked my nuclear materials course so I decided to jump right into the integration of mechanical systems in nuclear engineering this summer. I...

I have an electric air heater with a pressure loss of 3kPa (according to manufacturer at the flow rate and temperature I will be using). Air is supplied to the heater using a centrifugal fan with a static pressure of 8.7kPa (gauge) and a flow rate of 88m3/hr, giving a dynamic pressure of around...

The graph below shows the efficiency of an AIR CORE transformer at different voltages (from MAINS). At low voltages, it has high efficiency and gets lowers because of high magnetising current causing heat loss. But why is it higher at some points again? I do not understand this pattern. Please...

Hello, So say that I have a small four stroke engine that is designed to be kept static at ground level. I then take this engine and mount it to a small air plane, feeding the engine with either still air from inside the cabin (cargo) or the outside wind. The exhaust is fed out to the wind...

Homework Statement An object falls under gravity and air resistance force bv. It is known there is a characteristic time τ=m/b such that the object comes close to the terminal velocity for t>>τ. Derive an exact expression for the distance d traveled at time t. Homework Equations not sure...

Why are the blades of air plane propellers thin compared to ship propellers? Why shouldn't air planes use the same blade design?

Hi Air conditioners power should vary with thermostat and fan/Airflow rate levels. Is there data on Power vs BTU? Is it directly proportional? Thanks

Hi. I'm writing a space opera with your typical Star Trek-style shuttle. In the story, the ship is hit and begins leaking air. I want to knock out the characters (e.g., due to reduced oxygen before they can be rescued) without permanently injuring them due to loss of pressure or other effects...

So I've been reading about how plasma cutters work, and the way it ignites intrigued me and got me thinking. My question is, how conductive would a stream of ionized air created by a high voltage spark be? If you passed a high current, low voltage through the stream, would it be able to travel...

Hello, I have here a complex question. My background is Chemistry and Optoelectronics. I wasn't the best when we were studying Thermodynamics at uni so I have some knowledge-gaps. Anyways, here is my problem. Can somebody explain me the whole process of the convection in the coffee roaster. So...

Homework Statement [/B] This is a practical problem, no homework question. I'd like to determine pressure (and O2 partial pressure) at altitude, yet following a more realistic real-world calc including measured data like relative humidity (RH) and temperature at that altitude, yet all I can...

Homework Statement Consider the truncated cone tank submerged in water: inside the truncated cone tank there is air. Evaluate the forces acting on the truncated cone tank. Homework EquationsThe Attempt at a Solution The forces are the following Boyuant force : $$F_b= \rho_w g V_{tank}$$...

On June 30, 1908, the remote Siberian region of Tunguska made headline news when an explosion knocked down 80 million trees in an area of only 770 square miles. The mystery was that there was no crater, which led to the assumption that the space bomb responsible for the catastrophe detonated in...

Homework Statement The train is traveling in a gallery at ##v=70 km/h##. Outside air is not moving and pressure is ##p_0=101325 Pa## and temperature ##T=283 K ##. The area of the face of the train is ##A=9 m^2##. Determine the minimum area of the section of the gallery such that the pressure...

I need to know the maximum compression speed that can be applied to a rectangular bladder which has a open air port that will avoid rupturing the bladder. The bladder is 40" wide, 100" long, and 10" tall. The compression equipment is a large metal panel that is larger than the surface area of...

Homework Statement Would you see the same thin film interference pattern in a film of soap surrounded by air and a film of soap on glass? Why or why not? Homework Equations None The Attempt at a Solution Yes, you would see the same thin film interference pattern in a film of soap surrounded...

hi, I'm a student and I'm new comer of this forum. my question is about a my project for the university based on degassing a water flow. i know that i can use a vacuum pump or ultrasound to make this on calm water, but is it possible on flow water?

Homework Statement Bindi pops the cork off a bottle of champagne. The cork travels vertically into the air. She notices that the cork takes 4s to return to starting position. a) how long does cork take to reach maximum height? Homework Equations I know that a= -9.81m/s/s, and the final...

I'd posted more of a real world version of this question, involving greenhouses, a few days ago at... https://www.physicsforums.com/threads/is-greenhouse-interior-much-cooler-if-reflective-inside.875575/ ...but with no responses after 130 reads, I'm reducing it down to a barer and much better...

I wanted to inquire as to a thought I have on a situation with buoyancy and air pressure. In the first slide (slide 1), I am showing a situation where a buoyant object is pushing up on a support wall through a fixed wall that has water in it. Here are the factors: 1. The net buoyant force of...

Air Force Lug Analysis (section 9 here and summarized here) seems to be the best generalized method for comprehensive lug analysis. However, it relies on charts developed by the USAF in the late sixties. Every source I've found on the method uses those same images. I'm trying to make an...

I have a steelworks nearby my home. Is it possible to perform an air analysis in order to know how much the air is polluted? Which instrument do I need ? Are there cheap possibilities? Thanks a lot in advance for your help!