Fluid mechanics is considered to be one of the essential branches of Mechanical Engineering. Fluid Mechanics comprises two words, fluid, and mechanics, with different meanings and research criteria. In this article, I will extensively introduce fluid mechanics and its importance in daily life. So without wasting any time, let us start:
We remember in the early classes, we used to study three states of matter, and afterward, they became four named:
The definition of fluid is the state of matter that can be liquid or solid. We might have noticed that whenever the matter is in any stage, the criteria to know its state is to understand how much stress it can bear, and we name that stress as shear stress that changes its shape. But this situation mostly happens in solid or liquid cases. When the stress is applied, the substantial changes shape and reform into a new one. But up to a limit that cannot destroy its ultimate form. The stress applied to a solid is directly proportional to the strain, whereas, in liquids, the stress is directly proportional to the strain rate.
As mentioned that fluid mechanics comprises of two terms, so now I will define what mechanics is and how much it is essential in our today’s life.
Here are two essential terminologies:
The branch of mechanics in which bodies are at rest is called statics. It is a vast study of internal and external forces in a structure
Example:
The best example of statics is when you are standing on a plane on the rigid ground. The force of gravity and the reaction force as the reaction of gravitational force, both these forces act as statics and help in maintaining the state of rest.
The branch of mechanics which studies the bodies in motion is called dynamics. The study is all related to the movement and what is the cause of it.
Example:
The example of moving the body and dealing with all the forces that are acting on and their effect is categorized in dynamics.
Fluid Mechanics is the sub-category defining the fluid’s nature at rest or in motion.
The types of fluid mechanics are as follows:
Example:
It involves the mass flow rate of oil through the pipeline, study of the pattern weather forecast, and blood circulation.
Example:
The best example of fluid statics involves drinking with a straw. The mechanism happening inside is that when we reduce the pressure at the top of the straw, inside the liquid the atmosphere pushes the liquid up to the mouth.
Fluid statics and dynamics are divided into compressible and incompressible fluid as well as real and ideal fluids. So real is divided into the laminar and turbulent flow, and this goes on.
As I discussed earlier, fluid flow is classified, and they vary from type to type.
By reading their names, you get an idea of what a laminar and turbulent flow is. So laminar flow is one in which fluid flows smoothly without any turbulence. Usually, highly viscous fluid with low viscosity is characterized as laminar flow. Whereas turbulent flow is the one in which fluid flow is not smooth. And they have high velocities.
The compressible and incompressible flows depend upon one of the significant factors density. The flow is incompressible when the density is constant or nearly constant throughout the flow. Incompressible flows characterize most liquids. The compressible flows are opposite to the incompressible ones; they don’t have constant throughout. One of the best examples of compressible flow is gases.
In these types of flow, viscosity is one of the essential vital elements. Every fluid has some viscosity value. So the flows with a significant amount of frictional effect are said to be viscous. Inviscid flows are where viscosity is neglected or to some extent.
As the name shows, the flow covered with a solid boundary is considered internal flow. The liquid is flowing in a pipe or a wire. At the same time, the external flow is defined as an unbounded flow. The fluid flowing over the pipe or the fluid over the ball is exemplified as external flow. And the flow inside a pipe covered is said to be internal flow.
The names are enough to define the nature of the flows. So steady or uniform flows are said to be steady flows. And the unsteady one is opposite to the steady one that does not have any uniformity.
Natural flows are the one that flows naturally. But the theoretical example will be the one that flows due to the buoyancy effect. The forced fluids are the ones that are forced to flow with the help of external means. An example of forced flow is a fan or pump.
The nature of the fluid varies from type to type. The following are some vital types of fluids.
Real fluids possess viscosity. Viscosity is defined as resistance or opposition. Eliminating the ideal cases, all the fluids are examples of real fluids.
The ideal fluids are the one that has no viscosity at all. As I have mentioned just now that all the fluids have viscosity. So ideal fluids are just an ideal case study.
Both of them have two different properties. The Newtonian fluids are the ones in which the shear stress is directly proportional to the shear strain, and in non-Newtonian fluids, they are not proportional to each other.
The ideal plastic fluids are the ones in which shear stress is directly proportional to the shear strain. The shear stress value is also more than the yield value. These fluids are velocity gradient ones and have significant importance.
Fluid mechanics is considered one of the vast branches of mechanical engineering that covers all the fundamental laws of physics. It is not wrong to say those fluid mechanics depend on these laws, and they are named as follows:
Second Law of Thermodynamics
Conservation of mass
Conservation of linear momentum
Conservation of energy
Conservation of angular momentum
As I have briefly discussed all the types of fluids, the following is their graphical presentation.
The properties are one of the significant features of everything. The fluids also have some properties. The following are some essential properties of the fluid.
The word viscosity means thickness. According to the definition, viscosity is defined as the fluid’s property related to friction and resistance.
When one layer moves adjacently to the other, some friction exists, which we named viscosity. The layers are moving at some distance and are named dy. The velocities of the fluids are u and u+du, respectively.
The graphical presentation of the layer velocity versus the distance is shown below.
The graph will explain the trends of velocity and distance. As mentioned, two layers are moving adjacently to each other, so the layer that is on top imposes shear stress on the lower layer, and the lower layer, in response, causes shear stress on the upper one.
According to physics, density is defined as the mass to volume ratio. So the fluid mass to fluid volume ratio is the density of the fluid. In liquids, the density is constant, but in gases, it’s variable.
The specific weight is defined as the ratio between the weight of the fluid and volume. Thus the weight density is defined as the weight per unit volume of fluid and is denoted by w.
Mathematically,
w=Weight of FluidVolume of Fluid
w=Mass of Fluid×Acceleration due to cycleVol. of fluid
w=Mass of Fluid×gVol. of Fluid
w=ρg
The specific volume is defined as the volume of a fluid by a unit mass or volume. This property applies to gases.
Mathematically,
Specific Volume = Vol. of fluidMass of fluid
Specific Volume=1Mass of FluidVol.
Specific Volume=1
The thermodynamic property is the salient feature of gas and liquid. We know that when liquids are compressed, they form gas, so thermodynamics is one of the critical features of gases.
The equation below shows a connection between the pressure, specific volume, absolute temperature, and gas constant.
p=RT
The definition of a system is as follows:
The system is the quantity of matter or a specific region specified for research or study.
As you can see from the diagram, an imaginary or real wall or a surface separates the system from the surroundings. So a system can be open, close, or isolated (special case). So following is a brief explanation of all the types of systems.
Open System
In the open system, the volume is controlled and the energy and mass can easily pass through the boundary of the control volume.
Close System
In the closed system, the mass is controlled and cannot cross the boundary. The energy can cross the boundary easily and volume is also not fixed.
Isolated System
In the isolated system, the energy cannot cross the boundary.
The definition of dimensions is as follows:
The Definition of units is as follows:
There are two types of units explained below briefly.
Some basic dimensions are given the names and they are as follows:
Dimensions |
Units |
Mass |
m |
Temperature |
T |
Length |
L |
Time |
t |
Some dimensions are assigned names in terms of primary dimensions and they are as follows:
Dimensions |
Units |
Volume |
V |
Energy |
E |
Velocity |
V |
Two kinds of units are commonly used in today’s world and that is;
The English system does not have an apparent systematic and numerical base. It is considered to be one of the most difficult systems to memorize. In almost every country metric SI units are widely used but the United States is the only country that has not fully opted for the metric system rather they use the English system in many states.
Example
12 in =1 ft
1 mile =5280 ft
4 qt =1 gal
It is one of the most commonly used and feasible units. The metric SI units are widely used in industries and countries like England. There are seven basic fundamental dimensions introduced and their units in SI are as follows:
Dimension |
Unit |
Length |
meter (m) |
Mass |
Kilogram (kg) |
Time |
Second (s) |
Temperature |
Kelvin (K) |
Electric Current |
Ampere (A) |
Amount of light |
Candela (cd) |
Amount of Matter |
Mole (mol) |
There are numerous examples of fluid mechanics in our daily life. The following examples are some crucial parameters that cover fluid mechanics.
Our heart is an integral part of the human body that pumps blood to all body parts through arteries and veins. In this modern era of science and technology, many scientists have designed artificial hearts that work on the working principle of fluid dynamics and transmit blood and pumps like the original heart.
Our homes are one of the best examples of fluid mechanics. The piping, sewage, hot and cold water pipes, natural gas, and LPG work on fluid mechanics principles. Moreover, our refrigerator, air conditioning, heating, cooling, and insulating system are all examples of fluid mechanics.
We find various examples in our cars, planes, buses, and ships. Fluid mechanics covers all the fields associated with fuel transportation, from the fuel tanks to the cylinders, fuel pumps, carburetors, etc. It covers all the cooling heating systems of automobiles, lubrication systems, power steering, and radiator cooling.
Fluid mechanics is used in many medical devices such as glucose monitors, heart assistance devices, etc.
It is beneficial for eliminating pollution from the atmosphere, cleaning water, cleaning sewage systems, and controlling floods.
Hi Guys! Hope you’re well today. I welcome you on board. In this post, I’ll walk you through How to Optimize a PCB Panel Layout.
PCB panels are used in the manufacturing process to produce PCBs in large numbers. This not only reduces the overall cost but also makes the manufacturing process more efficient and reliable. PCB panelization is a manufacturing technique where multiple PCB designs are replicated on a single large board called a PCB panel. Then these individual boards are removed and depanelized from the panel to install them in the final product.
The number of panels is directly related to the overall manufacturing cost. To produce more panels, more cost will be required. However, it also depends on the shape of the board. If you require more boards of the same shape and size, it will reduce the panel cost since they all can be replicated and manufactured on a single panel.
Read on to find out how we can optimize the PCB panel layout to save both cost and time.
Let’s jump right in.
PCB panel is a large board that contains multiple instances of a small PCB. Know that the PCB panel is made up of the same material as the board and the panel size depends on the number of small boards you aim to produce. It is required to best use the panel space to produce PCBs in large numbers and to keep the unused panel space minimum. Since the more boards cover the overall panel space, the more efficient the manufacturing process will be.
You can pick the panel size as per your requirement. However, the most commonly used panel size is 18 x 24 inches. Normally, the boards are 0.100 inches apart in one panel. Panel designers need to be very careful while putting the PCB designs in the panel.
It is important to use your PCB design tools properly to avoid any hassle in the manufacturing process. Decisions made earlier during the PCB design process can go a long way and keep you from redesigning the entire board from scratch. These design tools can help you select the layer stack up configuration and PCB material. Additionally, they can help you transfer design data using open standard formats. Using this format manufacturer can exchange the design information with the PCB designers and can compile it in one file format.
To make the manufacturing process efficient, it’s better that PCB designers are in contact with the PCB panel designers. This way PCB designers can make some tweaks in the design to slightly alter its shape so multiple boards can effortlessly find a place in the panel to maximize the panel space.
Following points that every PCB designer should consider:
Hanging Components
Extra clearance is required for some components that overhang the board. It is created around the outline of the board placed in the panel. Creating extra room for clearance may slightly change the design of the panel. So it is better that designers contact in advance with the panel designers to figure out all the options.
Adding Features
The panel designer will add features to the panel like edge marks and tooling holes. PCB designer needs to make sure the placement of PCB designs doesn’t cause any problems.
Weight of Components
PCB panels carry some strength though, but they are not solid enough to withstand a large number of components. Since components come in various shapes and sizes. They vary from small to large size. The concentration of components may cause some problems and create a slight bend in the panel. Collaborate with the panel designers to explore other PCB layout options to handle a large number of components.
Width of the Board
The panel made up of thick board doesn’t cause a problem. It can deal with all manufacturing techniques applied on the array of the board. Trouble arises when thin boards are to be made for the final product. Thin boards produce a bend on the panel and can cause the solder to appear on the top of the boards. Consult with your panel designer if you want thin boards for your product. They may use a pallet and come up with another PCB layout option to deal with the thin boards.
Board edge clearance is another aspect to take into consideration while making the panel. It works as a shield for the board components and the copper and keeps them from being damaged.
Clearance in Breakout Tabs
PCBs are depanelized in two ways: by breakout tabs where small tabs are produced between the PCB designs. These tabs come with spacing between them on the panel. Both the copper and the components should have 0.125 inches clearance from the tab.
Clearance in V-grooves
Another method of depanelization is by cutting the V-grooves that are pre-scored V-shaped marks placed alongside the board edges. In V-grooves, the copper should come with 0.02 inches clearance and the components should exhibit 0.05 inches clearance.
FPC flexible boards are produced using three-panel methods namely:
Backward Panel
Conventional Panel
Oblique Panel
Panels are created to save material during the manufacturing process. Keep the distance between the boards minimum to effectively use the entire space of the panel. To accelerate the manufacturing process and to keep the entire panel process in check, a few things are included in the panel, like plate size, necessary instructions, and etching characters.
Each corner of the entire panel is drilled with a positioning hole to keep the board in place during the production process. For flexible boards, the panel width and the length should be 250mm. Since the larger board will lead to low production accuracy and eventually product failure.
An online world is flooded with scores of PCB fabrication houses. It’s difficult to find a diamond in the rough when all they claim to be the best in what they do. What we are going to share is our personal experience with the company called PCBWAY. They have an expert team who thoroughly hears your demand and guides you along the process to make an educated decision. The products are no less than quality. If you think what we say doesn’t really matter, then go and try it yourself, you’ll find the answer.
Apart from PCB prototype, they also offer PCBA (printed circuit board assembly) service so you don’t have to place components on the board. They come on board ready-made from the fabrication house.
If you want PCBs in large quantities, PCBWAY also offers PCB panel service. When you order a PCB panel, you can see a significant cost difference compared to if you want one PCB to be manufactured.
When you visit the called PCBWAY Fabrication House website, you see the following image with the option “Instant Quote”.
After writing the parameters in the given space, when you click the “Quote now” option you will come across the following page.
You can the option “Board Type” which is further divided into three categories with two options for PCB Panel. Either you can select the PCB panel by selecting the “Panel by Customer” option or you can ask PCBWAY to make the panel by selecting “Panel by PCBWAY”
You can select the size, quantity, number of layers, material, thickness and much more. Additionally, you can write down your further requirements in the “other special request” option. The primary aim is to give clear instructions so the final product exactly matches what you ordered in the first place.
Once you submit the order, it exhibits full detail on how your order is going to be processed, including order status, address, past orders, invoice details and the total time it’ll take to complete the order. There are no hidden charges, which means you’ll be charged exactly the price you’ll see in the order status. Plus, if you find any difficulty in placing the order or in the selection of the material, they will guide you to make the final decision.
The website comes with a live chat option through which you can communicate with the agent for any query. Though their English is not impeccable, but it still good enough to understand your questions and answer them properly. You can contact them any time from Monday to Friday, however, if you want to contact on the weekend, you can submit your email address and leave a message and they will get back to you within one business day.
Once the boards are manufactured, they go through a rigorous inspection test to ensure the quality of the product. This includes if the holes are properly drilled and aligned, the uniformity of the traces all the way through the board, and a thorough comparison with the design document to ensure that all the requirements are met. The inspection tools include an X-ray inspection machine, a flying probe tester, and an automated inspection machine. With 50 engineers on board, rest assured the final product gets the proper treatment it deserves.
As mentioned earlier, panels are used to produce PCBs in bulk. Moreover, they also refrain the boards from vibration and shock during the assembly process.
A simple coordination between the PCB designer and Panel designer can help build the PCB panels with accuracy and efficiency.
If you’re a newbie and just starting out, it’s better to get your PCB manufactured by the professionals in the PCB fabrication house. This will save you both time and money and you’ll learn many things along the process.
That’s all for today. Hope you find this article helpful. If you have any questions, you can ask me in the section below. I’d love to help you the best way I can. Thank you for reading the article.
There is no doubt that the traditional workplace has changed in a major way in the last few years. About half of companies now have remote workers. This means that managing a team looks different from what it ever did before. Facilitating the best of what a team has to offer, the synergies, the camaraderie, the collaboration, looks and feels different. It is sometimes difficult.
Those who manage remote teams are learning how to keep teams engaged and motivated, even as they work in isolation. Here are some of the techniques they are employing to keep their employees on track.
Working in the office made it easy and natural to casually ask questions, double-check information, and get feedback from colleagues. That ease made collaboration and the sharing of ideas more convenient. Managers who want to keep the teamwork going need to create situations in which employees have the chance to talk informally about work.
Scheduling a daily touch-base meeting , set up not to accomplish a specific task, but rather just to get aligned on the day, is vital. These daily meetings should be short and predictable. Every team member should know that this meeting is where they will be briefed or reminded about the big picture for the day and have the opportunity to make comments or ask questions about things the team is working on. To be clear, this is not a time to get into the details about how to accomplish a project, but rather a time to discuss teamwork in general.
In-person, co-workers can hear each other’s voice inflections, see body language, and generally understand more of the intent behind what someone is saying. Communicating through a computer screen takes away all those context clues. It’s really easy to misinterpret someone’s tone when you read a text or email.
The solution is to take zero shortcuts when it comes to communication . Don’t rush the email. Write in complete sentences. Avoid shorthand and abbreviations. Make it clear that if anyone has any questions, they are welcome and encouraged to ask. Thank employees who take the time to verify and clarify instructions.
Working from home might feel, to some employees, like they are always at work or that there are no boundaries for when to send emails. Being connected 24/7 should not make the team feel obligated to be available for work 24/7. Clearly communicate what the expectations are for when employees should be sending messages and also the timing of when they should be responding. For example, employees should respond within 3 hours of receiving a message between 9 a.m. and 5 p.m., but have no obligation to respond outside of those hours.
These rules will help the people communicating information and receiving information. They have the added benefit of building trust among team members and of making employees feel appreciated by the company.
Technology tools that help the team work as a team are the most important investment a company can make when it has remote employees. It’s not a place to scrimp. Companies are wise to look into software hosting services that allow any computer from any location to share desktop features, access to software, and the ability to work on shared documents. A good software hosting company will also provide security from hacking, cyber-attacks, and guard logins.
Having the right technology is so crucial that it should be a regular topic of conversation among teams and managers. Managers should regularly poll employees about how their current technology is meeting or not meeting their needs.
Even when everyone worked in the same office, managers understood that employees all have their own personalities, challenges, and styles. The era of working from home only adds to those differences. Not only do workers come to the job with their own personal uniqueness, but they now also bring their home lives to work, literally.
Some employees may live in areas with inconsistent internet connections. They may have pets, relatives, roommates, or alternative living arrangements. Their living space may not have the capacity for a dedicated workspace. They may live somewhere where getting some quiet or privacy is a struggle.
The way managers can combat these special needs is to shift the focus of work towards goals and deadlines, rather than pacing. Managers need to be more flexible. It’s not even possible to micromanage remote teams, so why try? Does it really matter if an employee is going to be distracted by his kids getting off the bus every afternoon as long as he puts in the time and effort to get his work done on time?
Remind the team why they are doing what they are doing. Understanding the purpose of the work is a huge motivator and will drive better performance.