The article will cover essential aspects of fluid statics and pressure forces applied to the fluid. The article will start with the absolute pressure gauge and the variation of pressure with depth in different gravitational field manometers and barometers, respectively. Then I will explain the forces that deal with fluids, such as hydrostatic force, buoyant force, etc. So, dear friends, without wasting any time, let’s start.
The definition of pressure according to fluid mechanics is as follows:
Pressure is the normal force applied by a fluid per unit area.
The units of pressure Pascal is too small to deal with in practical cases. For instance,
Kilopascal: 1kPa=103Pa
Mega Pascal: 1MPa=106Pa
The three common pressure units used are standard atmosphere bar and kilogram-force per square centimeter.
1bar=105Pa=0.1MPa=100kPa
1atm=101,325Pa=101.325kPa=101325 bars
1 kgf/cm2=9.807 N/ cm2=9.807×m2=9.807×104Pa
=0.9807bar
=0.9679 atm
The unit of pressure in the English system is pound-force per square inch (psi or lbf/in2)
The actual pressure at a given position is called absolute pressure. The pressure is measured relative to an absolute vacuum or absolute zero pressure.
The difference between the absolute and local atmospheric pressure is called gage pressure.
The pressure below the atmospheric pressure is called vacuum pressure.
All three of these pressures are interrelated with each. Other, and this is visible with the formulae as mentioned below:
Pvac=Patm-Pabs
Pgage=Patm-Pabs
The following diagram shows the relation of the pressures from the below-mentioned diagram:
We all know there is no fluid pressure change at rest and in the horizontal position. This phenomenon can further be elaborate on a few points:
Assuming a thin layer horizontally of fluid followed by force balance at any point. The pressure increases as the depth increase as there are more layers of fluids, and these layers are being balanced by the pressure increasing.
An example can explain the whole phenomenon.
Toto show how pressure changes with the change in depth. We assumed a rectangular fluid element, as shown in the diagram.
The length, width, and heights are mentioned on the diagram.
The pressure of the fluid is constant, whereas force balance in z direction vertically will be:
∑Fz=maz=0
P2△x-P1△x-ρg△x△z=0
Now, we will divide the above equation with delta x △xand will get the below-mentioned equation:
△P=P2-P1=ρg△z=sz
Here, one of the most important things is that the s is the specific weight of fluid.
The final statement to be noted is that there is an increase in pressure linearly with an increase in depth.
It is essential to note that the pressure force applied by the fluid is always normal at some points to the surface.
As pressure is a scalar quantity, sometimes it seems to be vector one. The pressure will be the same in any fluid at any point. To prove this point, let us discuss a scenario.
Let us consider fluid element (a wedge shape/ right-angled triangle) at equilibrium.
The mean pressures at three surfaces are mentioned as P1, P2, and P3, respectively.
The diagram shows the points clearly.
Here, the value along the pressure is the surface area.
According to Newton’s second law, the force in the direction of x and z is as follows as △y=1:
∑Fx=max=0 P1△z-P3Isinθ = 0 (1)
∑Fz=maz=0 P2△x-P3Icosθ-12ρg△x△z = 0 (2)
Here, the value of w is the weight of the fluid, and the value is as follows:
W=mg
W=ρg△x△z/2
The value of △x and △z are as follows:
x = I cos θ
△z=I sinθ
So, by substituting all the values in equations 1 and 2 and then diving equation 1 with △z and equation 2 with △x then, the final result will be:
P1-P3= 0 (3)
P2-P3-12ρg△z=0 (4)
Here, in equation 3 △, z drops to 0, and the final result will be:
P1=P2=P3=P
Numerous devices are used to measure fluid pressure and work on different principles. These devices are explained below briefly.
The definition of a manometer is explained as follows:
A manometer is a device in which fluid columns measure pressure differences.
The important key points about the manometer are explained below:
the manometer is used to measure small or moderate pressure differences.
If pressure is at a specific position inside any gas tank, then the pressure anywhere in the tank will be the same. But here important point to be noted is that it is for gases only as their gravitational effect is negligible.
The basic diagram of the manometer is shown as follows:
As we can see, two points in a basic barometer and a height h. So the pressure at point 1 will be the same throughout the tank so that P1=P2 and the pressure will be by the equation:
P2=Patm+ρgh
Here, h is the height of column fluid, which is in static equilibrium, and as we can see, the column is exposed to the atmosphere.
is the density of the fluid, and Patm is the atmospheric pressure.
Here, one important point to be noted is that the height of the tube is independent of the area of the tube.
The definition of the barometer is as follows:
A barometer is a device that is used for the measurement of atmospheric pressure.
The following are some important key points related to the barometer:
The structure of the barometer is the inversion of a tube filled with mercury in a container, which is exposed to the atmosphere.
The diagram shows the structure of the barometer;
Toto calculates the formula of the atmospheric pressure; we will follow the above diagram. As you can see, there is a point B, so this B equals atmospheric pressure. Point C inside the tube is assumed to have zero pressure as there are only mercury vapors above point C, and pressure above that point is low compared to the atmospheric pressure, so for ease, the pressure is taken to be zero. The formula of pressure is as follows:
Patm=ρgh
There are many other pressure-measuring devices that are in use in our daily life, and they are briefly explained as follows:
Bourdon Tube is a pressure measuring device consisting of a hook like a hollow metal tube that is connected to a dial indicator. There is a fluid inside the tube that is pressurized. When this fluid is being pressurized up to a point then the needle that is on the dial is deflected. The needle is read to zero when the tube is exposed to the atmosphere.
There are special types of pressure detectors that can convert the pressure effect into electrical energy and they are called pressure transducers.
When the mechanical pressure is created when the electric potential is applied to a crystalline form. Such kinds of devices are called Piezoelectric transducers.
Several manufacturing processes for plastic manufacturers and metalworkers, like milling or casting, produce burrs. However, to guarantee the safety and quality of a component, one needs to ensure smooth edges that will not cause any problems in further processing or use of the item. Deburring and brushing machines are solutions to this issue.
High-quality deburring technology from Germany can be integrated into casting and cutting machines, and to automatically produce flawless components.
Burrs are unwanted protrusions of a material like metal or resin that can develop during processing.
When picturing a component like a gear, it is easy to understand, that any kind of imperfection can cause serious problems for the machine the gear is used for. Here, we need to make sure it can rotate easily and will not grate and damage other machine parts.
For the safety of other products, assembly processes, and operators, we need to eliminate these imperfections and protrusions.
There are several materials and processes that can cause burrs to appear. This mostly applies to steel producers and metalworkers , as well as plastic manufacturers.
Burrs develop during:
Super Finishing,
Honing,
Grinding,
Broaching,
Milling,
Turning,
Boring,
Drilling,
Metal Sawing,
Pressing,
File Finishing,
Forging,
Casting,
Welding, and
Fusing.
For materials like:
Stainless Steel,
Steel,
Special Alloys,
Copper,
Brass,
Aluminum,
Sinter Metals, and
Synthetic Materials, like Plastic and Resin.
Multiple machines can help remove burrs; from small manual applications for low quantities to fully automated AI-driven deburring machines integrated into serial production.
The German-based company Loeser has used its over 80 years of experience to become the standard for automated deburring with over 500 installations worldwide. Their top-of-the-line automated deburring centers can be linked to computer-controlled wheel handling conveyors to enable a 20 % production increase.
Deburring machines can use several methods to create flawless components. Typically, the process has two to three steps:
Removing the Primary Burrs – This removes the protrusions that have been created during processing, for example with grinding.
Removing the Secondary Burrs – The grinding process can create secondary burs. With scotch brushes and abrasive brushing techniques, the workpiece’s original geometry can be restored, this time burr-free.
Rounding of Edges – This step is optional. The component now no longer has burrs, but still has sharp edges. If required, to reduce the risk of injury when handling the parts, a deburring machine can also round any edges.
There are different kinds of deburring machines and techniques. In general, the machine must be tailored to the individual industry processes and resulting items. Some types of component shapes and materials are better off with a specific deburring method than others.
A professional manufacturer of deburring machines like Loeser will help their clients find the ideal solution for their needs.
Deburring can be achieved via:
Manual deburring machines are small hand tools with curved or hooked sharp edges you can use to cut away burrs.
For punch deburring, you use a punch machine with a mold fitted to cut away the burrs of the created component. This technique is more efficient than manual deburring but does not allow complex shapes.
With the tumbling technique, parts are put in a rotating barrel along with water, compounding agents, and an abrasive media. Burrs get removed with the friction. The result is very fast and cost-efficient, but not very precise.
Like the tumbling technique, here, the components are subjected to a rotating wheel made from abrasive materials that remove protrusions on contact.
In thermal deburring, the burrs are removed by igniting a mixture of gas surrounding the components in a deburring chamber. This process is very fast but requires further processing such as surface treatments like pickling. Here, we also need to pay special attention to the correct mixture of the used gasses.
In electrochemical deburring, the deburring tool is an anodic metal dissolution with cathodes that dissolves the burrs. This technique is typically used to deburr hard-to-reach and very small areas.
During the hole deburring method, a spring-loaded cutting tool removes the burrs that have developed inside a hole, like the inside of a pipe. The component must be positioned very precisely for the cutting tool to go through the hole smoothly.
Brush deburring is a very cost-effective and fast method that can be used on complex shapes. Here, the components are deburred with brush tools, which may contain abrasive substances. Similar to using sandpaper manually, the machines can fit themselves into several shapes and create smooth and rounded edges. This is the most used technique for automated burring machines integrated into processing lines.
Deburring is a necessary process to remove unwanted accumulations of metal or other materials that can develop during various processing methods. Deburring machines remove the protrusions to guarantee safe handling and further processing of the components.
Automated deburring machines with brushes can be used to gain smooth-finished pieces right from the processing line. The German company Loeser has established itself as the leading manufacturer of efficient deburring processes, which can raise productivity by as much as 20 %.
However, today we will focus on the additive manufacturing technique and what you should look for during your search. Numerous businesses embrace the technology by delegating tasks to professional 3D printing services.
In the globally competitive environment, adding a supply partner to the company's value chain is the way to go because the technology is capital-intensive to implement. To help more businesses adopt the technology, we've created a simple guide to help them select the best 3D printing solutions partners.
Working with a 3D printing provider gives you direct exposure to a broad scope of 3D printing technologies. A 3D printing service can handle a wide range of industrial projects thanks to its extensive capabilities. As a result, one of the essential criteria in selecting the best 3D printing service for you is the wide variety of current technologies.
The service provider has significant expert knowledge in all technologies due to their broader technology scope. As a result, they can recommend and help consumers with the technology that will help them get the most out of their initiatives.
Choosing a 3D printing service isn't complete without considering the materials. Material considerations play an essential role in decision-making. Not all materials can be utilized successfully with all techniques.
Only some technologies can efficiently use solid materials. As a result, consider material availability when selecting a 3D printing service. The 3D printing service you hire should be experienced in printing with the required material.
The importance of design in 3D printing is frequently overlooked. While any design can be 3D printed, some can't be done well. Methods for additive manufacturing precepts should be used when designing for 3D printing.
A service agency must be aware of the difference and, as a result, strongly recommend or endorse design changes that are compatible with 3D printing. This compatibility can help customers save time, money, and materials while improving part effectiveness, longevity, and trustworthiness. As a result, choose a 3D printing service that specializes in design.
While contacting a 3D printing service with a wider variety of technologies is usually a good idea, it is not always the best option. Numerous service providers specialize in a specific area of expertise. This is commonly seen in medical and healthcare settings.
Medical implementations of 3D printing, as well as some aerospace implementations, must meet specific rules and regs. Service bureaus with FDA or ISO-approved amenities, technologies, materials, and procedures should be chosen for particular applications.
If you're working on a one-off 3D printing project, the 3D printing service you choose won't have an impact on your long-term work, product, or public image.
However, if you want to integrate 3D printing or outsource long-term work, finding the right 3D printing provider should be a priority.
Nowadays, more businesses across many industrial sectors adopt 3D printing as a viable alternative to subtractive manufacturing (acquiring machined parts online) and injection molding. We'll look at the benefits of 3D printing and how you can use this production method to benefit your company. Is it worthwhile to use 3D printing for your project?
One of the best aspects of 3d printing is the reduced labor costs. Operating costs heavily influence the quantity of money spent on building a structure. Whenever it comes to traditional manufacturing, production costs are incredibly high, and skilled machine operators are required. In 3D printers, however, all that is needed is for an operator to press a button, and the printer's automated process will take care of the rest. Furthermore, 3D printing is comparable to both small-scale and large-scale manufacturing.
Due to the speed and lower expenses of 3D printing, item life cycles are decreased. Organizations can improve and upgrade an item permitting them to convey better things in a more limited time.
3D printing permits the actual show of another item to clients and financial backers instead of passing it on to their minds, accordingly lessening the gamble of data being misconstrued or lost during communication.
It also enables low-cost test marketing, allowing prospective clients to provide feedback on a physical item without the risk of high upfront prototyping costs.
Traditional production techniques can lead to shoddy designs and, as a result, shoddy prototypes. Consider baking a cake where all of the ingredients are blended and mixed before being baked. If the ingredients were not extensively combined, the cake would have air bubbles or fail to bake thoroughly. The same thing can happen when using subtractive or injection techniques; quality isn't always guaranteed.
Because of the nature of 3D printing, it is possible to assemble a part or product step by step, resulting in improved design and higher quality parts/products.
Traditional manufacturing techniques are efficient at making dozens and dozens of identical items, but the models are devoid of life and repetitive.
While 3D printing allows designers to create unique models with limitless personalization, it also makes it easy to include unique features that customers demand. Meaning you can get precisely what you want after handing over your 3d printing quote to a form well-versed in this sector.
The majority of additive manufacturing's constraints relate to how to generate a print quickly enough to eliminate the need for support. As a result, developers are free to create intricate geometries and concepts.
3D printing is a cutting-edge technology that is preferable, cost-effective, speedier, more viable, adaptable, and environmentally friendly than previous generations. We currently reside in a fast-paced universe where everything needs to be done quickly, and 3D printing technology can help us turn our ideas to life; this is a massive advantage in the printing world.
Several industries use 3D Printers in printing various outputs they need; The industries include footwear, architecture, jewelry, construction and engineering, education, automotive, medical and dental industries, aerospace, and consumer products.
According to Woodford (2021), inkjet printers usually spray liquid ink, while a laser printer applies solid powder in its production. Well, a 3D printer does not use any of the two. Instead, it uses plastic in physical object modeling.
According to Formlabs (2021), the world's first 3D Printer is stereolithography, invented in the 1980s. Most professionals are still using the SLA technologies in production. The Stereolithography 3D Printer applies the photopolymerization process in its functioning; The process includes using a laser to cure liquid resin into hard plastics.
The Printer is popular because of its production ability of watertight, isotropic, and high-accuracy prototypes or parts. The parts or prototypes have advanced materials range with good quality features and smooth surface finishing. The Stereolithography resin offers vast mechanical, thermal, and optical elements to match the industrial, standard, and engineering thermoplastics properties.
Several industries use stereolithography—for example, dental, engineering, education, modeling, and manufacturing industries.
Stereolithography parts constitute a smooth surface finishing, fewer visible lines, and sharp edges.
Application of stereolithographyThe LCD 3D Printer uses UV LCDs arrays as its light source. The LCD panels produce light that directly shines onto the building area in a parallel fashion. Pixel distortion is not a problem in LCD 3D Printer because its light is not expanded. The printing quality is dependant on the LCD 3D Printer's density; increasing the pixels produces better quality (Leo, 2019).
The LCD 3D Printer has a faster building speed when compared to SLA 3D Printer; it prints parts faster.
A selective laser sintering (SLS) 3D Printers sinters small polymer powder particles to form a solid structure using a high-power laser. The SLS has unfused powder whose function supports the part when the Printer is printing and removes the need for a dedicated support structure. Hence, the SLS is suitable for complex geometries, including the negative and interior features, thin walls, and undercuts (Formlabs, 2021). The SLS 3D Printer produces parts with superb mechanical characteristics. Furthermore, it has strength that resembles the injection-molded parts' strength.
The SLS’s most common material is nylon. Nylon. Nylon has suitable properties that suit the SLS 3D Printer; the properties of nylon include it is flexible, strong, lightweight, and stable against chemicals, water, impact, UV light, and dirt.
According to Formlabs (2021), The SLS 3D Printer is popular among engineers because it combines high productivity, low cost per part, and established materials. The engineers use it for functional Prototyping. Furthermore, the SLS 3D Printer is cost-effective for bridge manufacturing or limited-run.
The SLS 3D printer parts have faintly rough surface finishing and layer lines that are almost not visible.
Applications of an SLS 3D printerFused Deposition Modelling (FDM) also refers to the Fused Filament Fabrication (FFF). Consumers popularly use FDM 3D Printer. The printer functions by releasing thermoplastic filaments like the Polylactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) via a heated nozzle, building a platform through heating the material to melt and applying the plastic on successive layers until completion of the part (Formlabs, 2021).
The FDM 3D printer is the most favorable for simple, low-cost Prototyping and basic proof-of-concept models. Compared to SLS and SLA 3D Printers, FDM 3D Printer has the lowest accuracy and resolution; hence, it is advisable not to use the FDM 3D printers in printing designs that are complex or have intricate features. Mechanical and chemical polishing processes are used in obtaining higher-quality surface finishes. An industrial mitigates challenging issues through soluble support and allows a wide variety of engineering thermoplastics, increasing production costs.
FDM parts show visible lines responsible for creating inaccuracies when handling complex features.
Application of FDM 3D printerA resin refers to a highly viscous substance of synthetic or plant origin typically converted into polymers; generally, the resin is a combination of organic compounds (Liqcreate, 2021). Transparent resin is mainly used in 3D printing in a transparent material. Transparent resin is suitable for 3D printing because of its water-resistant property. Also, the transparent resin is an ideal choice for that requires high quality, smooth finish, and fine surface.
According to Liqcreate (2021), several types of resin are used in 3D Printers basing on their functions or purpose. They include the general-purpose, premium, medical, castable, engineering, and creative purpose resin.
In the past, people used a lot of resources to study Software about modeling software. Some software is easy to use, and some are free to access. Some software use solid modeling whereby they produce manifold models. While other Software is watertight, a manifold model refers to a model with some thickness in all of its walls (Strikwerda, 2021). Softwares that use polygon modeling create walls with zero thickenings; such walls are suitable for creating graphics for movies and games contrasting with 3D printing. The polygon modeling software makes the manifold models, but it would need a lengthy procedure and more experience. The Software listed in the article generates 3D printable models. Some of the Software is easy to use. At the same time, others are more suitable for professionals rather than for amateurs.
According to Strikwerda (2021), Trinkercad software is a browser-based app and freely available to all users, and it applies solid modeling in its work. The creation of the Software targets beginners. Trinkercard software is unique because it introduces solid modeling and allows any person to make 3D printable modeling.
The Software applies the block-building concept. Therefore, it allows one to create models from a variety of basic shapes. The Software also provides aid to beginners through its guides and tutorials. Furthermore, the Software has the advantage of exporting or sharing with ease.
Trinkercad has an extensive library that constitutes millions of files that give the users several distinct options for finding the best shapes that will suit their problem requirements best. The Software allows the user to print and have the product instantly at your location through direct integration with other printing services. It is the best platform to learn about 3D modeling and printing.
According to Strikwerda (2021), Blender software is freely accessible to its users. The Software is not a solid model; it is open-source, rich in features, and constitutes animation, rendering, sculpting, video editing, simulation, and motion tracking. Also, the Software is very friendly since both advanced users and amateurs can use it.
The Blender Software constitutes many 3D creation facets, including simulation, animation, and modeling, e.t.c. The software suits individuals who are ready for transitioning from learning to designing complex 3D models.
One of Blender's exciting features is the photorealistic rendering feature. The feature creates models to reality; only a few free software can have such a feature.
According to Strikwerda (2021), the BRL-CAD Software is a type of Open-source Software. Also, it is an advanced solid model system comprising interactive geometry editing. The U.S military uses the BRL-CAD Software in modeling weapons and related systems. This shows the Software is very advanced and quite dependable. The Software serves its users with a precision of high level by using specific coordinates in arranging the geometric shapes.
The Software provides complex and simple shapes to its users to make their designs, having an extensive library of files. The Software allows combining multiple different forms to generate the desired model. BRL-CAD Software performs its tasks fast due to its dense features. Furthermore, it is free and available for access to all users.
According to Strikwerda (2021), Wings3D is an open-source software type; polygon modeling tool and has a broad range of selection and mesh tools regardless of its freeware. The Software is user-friendly, with beginners as the primary target; it has a steady learning curve. Its features, such as the easy-to-use interface and customizable hotkeys, indicate the designing or printing status; hence, the Software suits the starters.
The Software has no shortage of valuable or essential features like the inset or plane cut; thus, it can create impressive models. Moreover, the Software supports a vast range of both import or export file formats.
According to Strikwerda (2021), Modo 3D Printer software creates a creative 3D polygon modeling tool. Also, it can provide a subdivided surface designing tool that has more flexibilities for creating both the precision meshes and freeform organic designs through the use of the same Software. The Software is strictly used by professionals or advanced 3D printing users. The Software is not user-friendly, and it is costly to operate.
Modo has a wide variety of features and runs its processes smoothly. It has a very high speed in production and modeling. The Software allows extensions of partnering with other Software in production activities.
The price of a 3D printer varies based on the type of printer and the needs of the user. If you rank all of the many 3D printers on the market, you'll come up with a price of $400. However, as of April 2021, the price has dropped to $ 200-$500, with some being quite pricey at $ 1500. Professional 3D printers and enthusiast 3D printers, for example, range in price from $ 1,500 to $6,000, depending on the printing capability. Finally, industrial 3D printers are expensive to buy and operate, ranging from $20,000 to $100,000.
So, that was all for today. I hope you have enjoyed today's lecture. If you have any questions, please ask in the comments. Take care.A 3D object can be defined as,
"An object or structure that has three dimensions which includes width, length, and height."
As you are now familiar with the term 3D we shall proceed further with our actual topic, so
Here we have the most commonly asked question of all, what is 3D printing?
3D printing can be defined as;
