Sizing Definition and 136 Threads

I’m not really sure where to ask this, but here goes: I am trying to find a topic to read on which explains the behavior of brass during reloading (an activity that’s part of recreational shooting). Shooters who handload recycle brass by refilling brass cases with new primers, smokeless...

I'm with a home study structural engineering as an electrical engineer. The assignment that I am trying to do is calculating a frame to support a large pipe with a weight of 32,000 kN distributed across eight legs. ( so it on a job site) I've performed a detailed analysis of the forces using...

Good afternoon, How should an upstream isolation transformer be sized for a dc power supply? For example, if we have a power supply with the following specs: Input Voltage: 120 VAC Input Current: 2 Amps Inrush Current: 22 Amps Efficiency: 90% Power Factor: 0.55 Output Voltage: 24 VDC Output...

Hi all, I'm a tinkerer with no formal engineering background, but enjoy read about physics and engineering in general. I'm reading up on fluid flow and I'm a bit grasping at the concepts. As far as I understand it, flow rate, pressure drop and pipe size are all interrelated, where one affects...

I am going to have several series/parallel capacitors so need balancing resistors. I understand that for series capacitors, it is wise to use voltage balancing resistors so mismatch in individual series capacitors leakage current can flow through the resistors which prevents individual...

I'm involved in purchasing a set of mixers for crude oil storage tank. The tank volume is around 98,500 cubic meter. The main purpose of the mixers is base Sediment & water control (cleaning). Deferent vendors offered different number of mixers with different required horsepower. I'm looking...

Please don’t laugh, this may sound a trivial question, but it is important. I have seen so many conflicting opinions, even from manufacturers. Some say, just use the biggest bore possible, others say use a small bore 8mm for a fully pumped system & a large bore 11mm for a gravity system. There...

A friend has a single phase, cap start induction motor with the following characteristics: V 240/250 A 2.6 Hp 1/3 Rpm 1435 @ 50Hz As for as I know it’s not fitted to a machine, but given the low hp rating I’d guess it’s for a drill press. So it would need only moderate to low starting torque...

I understand that when sizing balancing resistors you should consider the power rating of the resistors. The resistance and power rating has to be high enough so that they do not overheat. Even with a large enough power rating, I know that they will effect your overall efficiency since that's...

Working out as follows x= (20-6)/20 = 0.7 Fk = k / air specific heat ratio Fk = 1.31/1.4 Fk = 0.94 xT = Fk * x 0.94 x 0.7 = 0.658 because xT < x = 0.658<0.7 flow through the valve is choked Expansion factor Y Y = 1 - x/( 3 x Fk x xT ) Y= 1- 0.7/( 3 x 0.94 x 0.658) Y = 0.623...

I have two filter materials and I have manufacturer-supplied pressure drops across the filters at given flow rates. I know the desired flow rate and the negative pressure "sucking" on the downstream side of the filter, and I want to calculate the required filter surface area for each filter...

I am trying to determine the size of a single cartridge heater or 2 cartridge heaters to heat a large mass of aluminum to 400F. The aluminum block will be sitting inside an insulated (all sides) enclosure. The following are the specs for this problem. - Max surface temp of aluminum block is...

I was wondering if it was possible to determine the size of a manifold globally. Suppose I had a manifold that sits in 3 dimensions. I could construct a Euclidean space around in the same space and be able to say things of the dimensions right?

The robot weight is 900kg I have a robot with max reach swinging around with a weight of 110kg at the end at 125 degree/s I am not sure if the anchors I use are strong enough to hold it down assuming i mount the robot at the centre of the mounting plate Any advice with doing calculations to do a...

Summary: Hello; i am trying to work my way thru some motor sizing calculations on a semi-simple example so that i can more easily do it in the future. Could i get some guidance? Hello: I am trying to develop a good system for sizing motors (generally steppers). In the past i just guesstimated...

I'm contemplating extending the concept of corner reflectors to wavelengths in the audible spectrum, specifically road noise. I read somewhere that road noise is predominantly between 800 Hz and 1300 Hz. The corresponding wavelengths (at 20°C) are 16.9 inches and 10.4 inches. I read elsewhere...

Hello, I want to size my system to be able to get rid of fluids without any head buildup within the container. I am just a bit confused as to what formula I should use. My problem is summed up in the following schematic. Note that P1>P2, I have assumed H=10^(-4)m and my flow rate is 0.1 m3/s...

Can someone please help me to size the parentheses so they stretch appropriately around the column vectors in the expression/equation: $$\text{det} ( v_1, \cdot \cdot \cdot , v_n ) = \text{det} ( \begin{bmatrix} a_{ 11} \\ \ \\ . \\ . \\ . \\ \ \\ a_{n1} \end{bmatrix} , \cdot \cdot \cdot...

Hi Everyone! I designed a motor fan system pulley system. So, basically, the motor is of 15 kw with a driver pulley of 7" dia. And through a v-belt I attached a backward curved fan with a 10" dia pulley on the shaft. My fan shaft power is 13.24 kw. This selection was given to me by the software...

Not sure if this is better suited for the electrical engineers or mechanical but I figured id post it up here to start. I am looking to size a motor that will spin a box which weighs about 600lbs. The motor needs to be in line with the boxes rotational axis. It needs to be able to rotate 360...

Homework Statement There is a 1 kg (52x52x52mm) square block attached to a 200 mm long (d = 8 mm, weight = 0.03 kg) rod what is connected to an electric motor. The setup is vertical and needs to achieve about 90 rpm. So, the 1 kg square block will circle on the outer rim, connected to the...

What's the difference between zone sizing data and terminal unit sizing data in HAP and is it possible that the maximum cooling sensible load for the zone be greater than the Sensible coil load of the terminal unit as indicated in the system design report attached .Note that it is a single space...

In a recent post on the Analysis Forum I tried the following Latex code in order to size the \mid signs ...\left\mid \frac{f_j ( a + h ) - f_j (a)}{ h } - x_j \right\mid^2 \le \| \frac{ f( a + h ) - f(a) }{ h } - ( x_1, \ ... \ ... \ , x_m ) \|^2 The code failed ... but why?Can someone...

If I have a 7.5HP motor running at 1750rpm with a pulley and v-belt and connect it to a gearbox, where the right angle worm gearbox sees an input speed of 580rpm, how would I go about sizing the gearbox? Am I correct to say that I would size the gearbox for the lower input speed and more...

Homework Statement A mass of 115kg is to be suspended from a spring. When the mass increases to 575kg, the spring will move. Find the spring constant k. (This is not from a textbook, it is a project problem for a vehicle unloaded and then loaded on the same spring). y1 is the maximum height I...

Hello All, I have come across a problem, which has troubled me for some time now. What needs to be done is the following: A mass on a rod 0.6m (mass less) has a mass of 1 kgr attached at the end of it. The rod needs to be rotated 60 degrees, within t=120 sec (see image). What I would like to...

Hi.. i am working on a developemnt of electric vehicle as my final year project..i have calculated the max. power required by 800 kg vehicle is 30 kw.. so i am using 30 kw 3 phase AC induction motor.. now can you please help me out in sizing my battery pack.. weight : 800kg max. velocity : 80...

On older GM cars, the brake lines are 3/16" from the front port of the master cylinder, splitting into two 3/16" for each front wheel, and 1/4" from the rear port of the master cylinder, splitting into two 3/16" for each rear wheel. This is the case for drum/drum or disc/drum configurations...

Hello, I have a Coen Duct burner system that requires a continuous flow of 120 scfm @ 5psi above duct pressure. Duct pressure is about 3 inwc. We have 6 pilots that will have a 1/2" inlet for the air. Our plant air system can supply 120psig and about 400 scfm. My issue is figuring out what...

I am sizing a linear actuator to build a BMX gate. Please see the drawing below. I have a metal gate that is 20" tall and 9.5' wide. It will be steel and weigh approximately 150lbs. I am mounting the rear of the linear actuator on a clevis 8" off the ground. The front will be mounted with...

Hi, Interested in sizing some DC lithium-ion batteries (through a controller) to power the following system: 90KVA, 200/115 Volts AC, 400 Hz, 3-phase. The current approaches I've taken have been drastically oversized so I'm clearly missing something. Cheers, J.

Hello, I am having a hard time deciding the size of a solar array to boil water for a school project. Before putting any thought into the subject I simply thought that I would just take the wattage of the panels and add them up since they are added in both series or parallel and then select an...

Good Day Guys, I need help in checking the beam size required to transport a cargo. What checks do i do? 1. Check actual BM with resisting moment of the beam 2. Check actual shear with the resisting moment of the beam How do i calculate following if I only know the type of beam used, i.e...

I want to design the installation of a 500KVA Distribution Transformer to supply a neighborhood in Nigeria. The Existing National Grid voltage is 11KV. I want input from you guys to add to my sizing/costing. Inputs: 1. Sizing of XLPE Cable 2. Sizing of Transformer HV Protection ( Current Rating...

I have a system that will require 3 different gearboxes. Starting on the right we have a roll of felt that is 36 inches in diameter and weighs 4000lbs. The felt is going to be fed into the table in the middle off of roll number 1 on the right by gearbox number 2. Once the felt is cut, gearbox...

Hi all great PF members, Can anyone help me to sizing fan static pressure strong enough to open a metal cover an angle 15 degree at the end of the duct (20m in length with few 90 degree bends), I'm really not good at math so any help are greatly appreciated. Please refer to sketch attached for...

Homework Statement How does the method of cable installation and other external factors influence the required cable cross sectional area for a given circuit Homework EquationsThe Attempt at a Solution I've been searching for the answer for this for ages. I only find answer relating to types...

In tube end forming practices, is it possible to first reduce the diameter of the pipe (tube 0.9mm thick) and then expand it, at the same end, by about 1mm in total, with a transistion radius of 8mm ? Please see attached image. Though it might be exaggerated, but the image should suffice. I want...

Hi guys, I have question regarding cooling towers. I have been asked to check if cooling towers would be efficient and economical to cooling system for a power plant to be installed in Weymouth, England. As per my calculations, heat to be rejected (in the condenser) from the system is 20 MW...

I'm trying to figure a range of flows of coolant that will pull 200,000 Joules per minute from a heat exchanger cooling oil. The oil is passing through a head that adds 200,000 Joules per minute to 0.5 L / min. The 0.5 L is dumped into a sump with ~7 gallons of oil. The oil then passes...

Hi, I need to size a CSTR for the transesterification of tri-glycerides into methyl esters (bio-diesel) by reaction with methanol and NaOH catalyst. The transesterification reaction taken place in 3 reversible steps: TG + CH3OH <--> DG + ME DG + CH3OH <--> MG + ME MG + CH3OH <--> C3H8O3 + ME...

Dear all, I would like to have your help for a problem that i face. I know that it is a little bit ridiculous, but my brain is stacked right now! I have a helium compressor that i want to fill it with helium at room temperature 293K @ 1.013bar. This compressor will be connected with a pipe. As...

Hi, I'm new here and I'm here to seek for help... I have this school project, I'm supposed to create an app (Funny that they asked an engineering student to do programming huh?). Basically this app involves beam calculations. It's supposed to suggest an appropriate beam sizing ( the cross...

Homework Statement In the attachment. Homework Equations Chart of pressure loss due to friction for steel ducts : http://postimg.org/image/4iml9x761/ The Attempt at a Solution I don't understand the deltaP/L column of the results table. Where did the values come from? Shouldn't they all be...

Hi! I have a homework problem that I'm stuck on. The question asks: My code is able to output the first three numbers in the vector, but it won't output the last one. This is what I have so far: #include <iostream> #include <vector> using namespace std; int main() { vector<int>...

Hello, I'm in the design phase of a greenhouse building and am tossing around the idea of not using lumber. I have put up many stick built structures but am afraid the humidity will rapidly decay a conventional pine/fir. And I want to avoid pressure treated if possible Based on a roofing...

Hi, I'm trying to size up a suction line, for a positive displacement gear pump. I'm flowing 3.4 GPM. The oil I'm looking at using is Case IH Hy-tran. It has a SUS # of 208 at 100 degrees F and 47 at 210 degrees F. cSt of 40 at 40 degrees C and 6.3 at 100 degrees C. I have sized up a 7/8"...

I have obtained the volume of my CSTR, how do I calculate the height and diameter of it? Is there a certain ratio to adhere to for better mixing? Tried reading up the rules of thumbs but no info on that. Tried searching other books too but to no avail.

Hi, I have just got into the battery industry and i would like to understand a few things especially when it comes to sizing a battery. For example: if i have a load of 1600W and the system voltage is -48V DC (for a telecom application). The main supply is AC which is converted into DC through...