A Journal of Applied Mechanics and Mathematics by DrD, # 44
Machinery Dynamics Research, 2017
Mouse Trap / Pendulum Dynamics Challenge - Part I
Mice are a problem all over the world, and as a result, I'm sure that there are mouse traps of various sorts found everywhere. It would be utterly amazing if this were not true! In the USA, there is a very common type of mouse trap that I have seen used all my life, the sort of system
A Journal of Applied Mechanics and Mathematics by DrD, #43
(c) Machinery Dynamics Research, 2017
Four-Bar / Toggle Linkage Mechanism
I believe that it would be correct to say that all of the single degree of freedom mechanisms that I have discussed on ME Forums have involved only a single loop. This might lead a reader to conclude that a single degree of freedom implies only a single loop, and vice versa, that a single loop imp
A Journal of Applied Mechanics and Mathematics by DrD
July 31, 2017
Over at the Kinematics of Machines club, I recently ask if anyone could show me an example of a four-bar linkage that would be classed as a triple rocker. In the terminology of four-bar linkages, a link is classed as either a crank or a rocker:
Crank - can rotate in a complete circle
Rocker - cannot rotate in a complete circle]
Thus my question was for an example
An engine or motor is a machine,designed to convert one form of energy into mechanical energy.Heat engine burn a fuel to create heat, which is then used to create a force. Electric motors convert electrical energy into mechanical motion; pneumatic motors use compressed air and clockwise motors in wind up toys use elastic energy. In biological systems, molecular motors, like myosins in muscles, use chemical energy to create forces and eventually motion.
Agriculture is the backbone of the strong economy. Agriculture is demographically the broadest sector and plays an important role in the overall economic development in India since India ranks second worldwide in farm outputs. So, this is another Mechanical Startup Story from the Agriculture based start-up Sickle Innovations.
Sickle Innovations started in 2014 by the encouragement of Centre for Product Design and Manufacturing and Indian Institute of Science Bangalore. Since in Indian demog
Holla People!!!! Since it has been a long time I was waiting for starting the blog on Mechanical Startups, my first entry to the new blog starts with the few hardware startups in India. ATHER ENERGY is a privately owned founded by Swapnil Jain and Tarun Mehta in 2013 headquartered in Bangalore Karnataka.
This budding startup has received fundings from Hero Motocorp, Tiger Global & Flipkart. Profoundly being a part of Automotive industry and producing electric vehicles, in the in-house
A Journal of Applied Mechanics and Mathematics by DrD, #41
(c) Machinery Dynamics Research, July 2017
What do you know about hysteresis? Many Mechanical Engineers will associate this term with the magnetization curve of a piece of magnetic material, and quickly conclude, "I don't have to worry about that!" But that would be wrong. While hysteresis does occur in magnetic systems, it happens in many other situatio
A Journal of Applied Mechanics and Mathematics by DrD, #40
Two Short Math Problems
Do you ever read the ads that appear on ME Forum? I try to avoid them as much as possible, but an organization called BRILLIANT has put up some interesting math problems of late that have caught my eye. Two of them are the subject of today's post.
The first problem that I want to discuss is actually more recent than the other, but it gives us a good plac
A Journal of Applied Mechanics and Mathematics by DrD, #39
(c) Machinery Dynamics Research, 2017
Comments on a Textbook Theory of Machines
R.S. Khurmi & J.K. Gupta
Recently, through the wonders of the Internet, I have come across a copy of the textbook Theory of Machines by R.S. Khurmi and J.K. Gupta (S.Chand & Co., Ltd., 2005). Since theory of machines has been my primary technical interest since the early 1980s, I was interested
A Journal of Applied Mechanics and Mathematics by DrD, #38
Machinery Dynamics Research, 2017
Rocket Homework Problem
Most engineers find problems involving rockets to be exciting. There is something about a rocket that fires our imagination, whether we think of going to the moon or one of the planets, or simply of shooting down an incoming missile. The subject of this post involves a rocket on a mobile launcher. The rocket is i
Where Would You Publish It?
Since long before my time, there has been a desire to have important results published where they become accessible to many others. Some of the great names, such as Newton, Euler, Bernoulli, and others, we know primarily because of what they published. Their work formed the fundamentals upon which modern engineering and science is built. Publication of research results has long been particularly important to faculty members; it is often take
The link below is an article about the value of certification for manufacturers. It is a heavy sell for certification. In my opinion it misses the most basic benefit of certification, which is the path to getting certified.
This came to me via e-mail. I am sure little of this is 100% correct. But just think if just 50% are 50% correct.
The Exponential Age?
Just a few things for us all to ponder, especially the younger ones amongst us.
Did you think back in 1998 that 3 years later you would never take pictures on film again?
In 1998 Kodak had 170,000 employees and sold 85 % photo paper worldwide. Within just a few years their business model disappeared and they went bankrupt. Wha
A Journal of Applied Mechanics and Mathematics by DrD, # 37
29 April 2017
Two Balls Rolling On An Incline
A Problem Where I Learned Something New
In previous articles, I have mentioned another web site called Physics Forums (PF) where people post problems for which they need help. In this note, I want to present to you one such problem and it solution, along with a new insight that came from another commenter at PF, one of the advi
what is the difference between refrigeration and air conditioning?
A major difference between refrigeration and air conditioning is the point of supply for the gases. Refrigeration systems have gas installed in a series of tubes. In old refrigerators, this gas was chloro-flouro-carbon, or CFC, but this has harmful effects on people, so refrigerators not contain HFC-134a. HFC-134a is the sole gas used as a coolant in refrigeration systems. Air conditioning systems use built-in chemicals, bu
La fabricación de piezas por maquinado
Todo ingeniero debe tener una cultura general integral y, dentro de esta, como es lógico, una cultura de la profesión. Parte de la cultura del ingeniero mecánico consiste en conocer la historia de la ingeniería, y en el caso particular de este blog es importante comenzar por conocer muy brevemente la historia de las máquinas herramienta. Para ello se presentará más adelante el anexo I, el cual trata sob
1. In a steam turbine, the ............ is allowed to rotate?
2. Which valve controls the flow of steam into the turbine?
3. The blades in a ............... turbine are designed so that the pressure below the blade is always higher than the pressure above which causes them to move (or spin) as high velocity fluid flows through them.
4. Where in the steam path is the energy transferred from the steam to the turbine?
5. There is excessive corrosion
Recently I was interviewed by a Mechanical Engineering student on the importance of communications. I’m approaching 40 years in engineering practice so the examples began to flow and the student’s 15 minute time estimate for the meeting quickly turned into two hours. The meeting itself was a lesson in communications. My awareness of the root cause, that I will describe below, I believe made the information more valuable.
The student and I covered many issues on the topic of communications,
A Journal of Applied Mechanics and Mathematics by DrD, #36
Base Acceleration Problem
In a recent post (#35) I mentioned that I often participate in another forum called Physics Forums (PF). The problem that I want to discuss here is an elaboration on a problem that recently appeared at PF. I'm going to add a little bit of complexity to the problem (the problme as stated at PF was extremely simple) in order to make a particular point.