Archive for the ‘Projects’ Category

Building performance analyses in Energy3D

April 6th, 2014 by Charles Xie
Energy3D (Tree image credit: SketchUp Warehouse and Ethan McElroy)
A zero-energy building is a building with zero net energy consumption over a year. In other words, the total amount of energy used by the building on an annual basis is equal to or even less than the amount of renewable energy it produces through solar panels or wind turbines. A building that produces more renewable energy than it consumes over the course of a year is sometimes also called an energy-plus building. Highly energy-efficient buildings hold a crucial key to a sustainable future.


One of the goals of our Energy3D software is to provide a powerful software environment that students can use to learn about how to build a sustainable world (or understand what it takes to build such a world). Energy3D is unique because it is based on computational building physics, done in real time to produce interesting heat map visualization resembling infrared thermography. The connections to basic science concepts such as heat and temperature make the tool widely applicable in schools. Furthermore, at a time when teachers are required by the new science standards to teach basic engineering concepts and skills in classrooms, this tool may be even more relevant and useful. The easy-to-use user interface enables students to rapidly sketch up buildings of various shapes, creating a deep design space that provides many opportunities of exploration, inquiry, and learning.


In the latest version of Energy3D (Version 3.0), students can compute the energy gains, losses, and usages of a building over the course of a year. These data can be used to analyze the energy performance of the building under design. These results can help students decide their next steps in a complex design project. Without these simulation data to rationalize design choices, students' design processes would be speculative or random.

A complex engineering design project usually has many elements and variables. Supporting students to investigate each individual element or variable is key to helping them develop an understanding of the related concept. Situating this investigation in a design project enables students to explore the role of each concept on system performance. With the analytic tools in Energy3D, students can pick an individual building component such as a window or a solar panel and then analyze its energy performance. This kind of analysis can help students determine, for example, where a solar panel should be installed and which direction it should face. The video in this post shows how these analytic tools in Energy3D work.

Spring is here, let there be trees!

March 28th, 2014 by Charles Xie
Trees in Energy3D.
Trees around a house not only add natural beauty but also increase energy efficiency. Deciduous trees to the south of a house let sunlight shine into the house through south-facing windows in the winter while blocking sunlight in the summer, thus providing a simple but effective solution that attains both passive heating and passive cooling using the trees' shedding cycles. Trees to the west and east of a house can also create significant shading to help keep the house cool in the summer. All together, a well-planed landscape can reduce the temperature of a house in a hot day by up to 20°C.

The tree to the south side shades the house in the summer.
With the latest version of Energy3D, students can add trees in designs. As shown in the second image in this blog post, the Solar Irradiation Simulator in Energy3D can visualize how trees shade the house and provide passive cooling in the summer.

The Solar Irradiation Simulator also provides numeric results to help students make design decisions. The calculated data show that the tree to the south of the house is able to reduce the sunlight shined through the window on the first floor that is closest to it by almost 90%. Students can do this easily by adding and removing the tree, re-run the simulation, and then compare the numbers. They will be able to add trees of different heights and types (deciduous or evergreen). There will be a lot of design variables that students can choose and test.

A design challenge is to combine windows, solar panels, and trees to reduce the yearly cost of a building to nearly zero or even negative (meaning that the owner of the house actually makes money by giving unused energy produced by the solar panels to the utility company). This is no longer just a possibility -- it has been a reality, even in a northern state like Massachusetts!

Energy3D in France and Energy3D User’s Guide

February 24th, 2014 by Charles Xie
Solar irradiation simulations of urban clusters in Energy3D.
More than four years ago, I blogged about our ideas to develop a computer-aided design (CAD) program for education that is different from SketchUp. We wanted a CAD program that allows students to easily and quickly perform physical analyses to test the functions of their 3D models while constructing them -- in contrast to typical industry practices that involve pre-processing, numerical simulation, and then post-processing. We thought closing the gap between construction and analysis is fundamentally important because students need instantaneous feedback from some authentic scientific computation to guide their next design steps. Without such a feedback loop, students will not be able to know whether their computer designs will function or not -- in the way permitted by science, even if they can design the forms well.

Four years after Saeid Nourian and I started to develop our Energy3D CAD program, we received the following comment from Sébastien Canet, a teacher from Académie de Nantes:
"I am a French STEM teacher and a trainer of technical education teachers in west France. Our teachers loved your software! We were working on an 'eco-quartier' with the goal to use as much passive solar energy as possible. Each student worked with SketchUp to model his/her house and then pasted the model on a map. Then we tested different solar orientations. Your software is a really good complementary tool to SketchUp, though the purposes are not the same. It is fast, easy to use, and perfect for constructing!!! I will use it instead of SketchUp in our activities."

Sébastien wrote that, if we can provide a French version, there would be hundreds of French STEM teachers who will adopt our software through his Académie. We are really happy to know that people have started to compare Energy3D with SketchUp and are even considering using Energy3D instead of SketchUp. This might be a small change to those users who make the switch but it is a big thing to us.

On  a separate note, we just finished the initial version of the User's Guide for Energy3D. We intend this to eventually grow into a book that will be useful to teachers who must, upon the requirement of the Next Generation Science Standards, teach some engineering design in K-12 schools. Our recent experiences working with high school teachers in Massachusetts show the lack of practical engineering materials tailor-made for high school students. As a result, one of the teachers with whom we are collaborating has to use a college textbook on architectural engineering. Perhaps we can provide a book that will fill this gap -- with a student-friendly CAD program to support it.

A high school student’s design work with Energy3D

February 22nd, 2014 by Charles Xie
Cormac Paterson is a student at Arlington High School. We ran into him last year while conducting research in the school. He quickly mastered our Energy3D CAD software. In as short as just five class periods, he came up with three different architectural designs that appear to be very sophisticated and impressive (see the second row in the image). After that, Mr. Paterson continued his creative work with Energy3D. In his latest projects, he designed a Mars colony and a solar tree. Many of his design elements surprised us: As the developers of the CAD software, we didn't even know that it could do those things until we saw his designs!

Thanks to the National Science Foundation, we obtained a bit more funding to deepen our research on engineering design. We are extremely interested in studying Mr. Paterson's gift in architectural design: What makes him such an extraordinary designer as a high school student? Since our Energy3D software can monitor every move of the designer, we may be able to find some clues from the data generated in his design processes.

Note: We are very serious in protecting the privacy of minors. In this case, we have obtained a permission from Mr. Paterson's parent to feature him and his work.

Getting sensor data out of Energy2D

February 9th, 2014 by Charles Xie
Figure 1: Copy data from Energy2D.
Since a few users asked if the simulation data in Energy2D can be exported to other applications such as Excel, I have added a feature to the app for extracting virtual sensor data as multi-column time series data. For the user's convenience, there are three different ways of getting these data:
  1. When right-clicking on a sensor, the "View Data..." from the popup menu returns the data that has been recorded by the selected sensor.
  2. When right-clicking on a spot not occupied by a sensor, the "View Data..." from the popup menu returns a tabbed pane that contains all the sensor data -- different types of sensor are organized in different tabs.
  3. When the translucent graph is open, clicking the View Data button on the graph window's control panel returns the data recorded by all the sensors of the selected type, in consistent with the current display of the data in the graph window.
Figure 2: Paste data into Excel.
Regardless of which way you use, use the "Copy Data" button at the bottom of the data window to copy the data (Figure 1) and paste it into Excel. Once you get the data into Excel, you can process and plot them in any way you want (Figure 2). This feature is very handy if you need to combine data from multiple simulations into a single graph.

Note: This feature only works for the app. For security reason, the embedded applet is not allowed to access the System Clipboard (this is understandable, because people often copy and paste important information!)

Using Dynamic Models to Discover the Past (and the Future?)

December 16th, 2011 by Sarah Pryputniewicz

What was Earth like 2.8 billion years ago?  The first life was emerging on the planet.  The Sun was weaker than it is today, but geologic evidence shows that the climate was as warm (or warmer) than it is today.  Was Earth colder because of the weak Sun, or warmer, as geologic evidence suggests?  How did this affect how life arose?

A new 3-D model of early Earth suggests that the planet underwent significant changes–from very warm to very cold.  Past models were one-dimensional–holding constant the amount of cloud cover or sea ice–to make the calculations easier.  But with more advanced computing, researchers at the University of Colorado Boulder were able to make better models of the planet’s climate.

“The inclusion of dynamic sea ice makes it harder to keep the early Earth warm in our 3-D model,” Eric Wolf, doctoral student at CU-Boulder’s atmospheric and oceanic sciences department, said. “Stable, global mean temperatures below 55 degrees Fahrenheit are not possible, as the system will slowly succumb to expanding sea ice and cooling temperatures. As sea ice expands, the planet surface becomes highly reflective and less solar energy is absorbed, temperatures cool, and sea ice continues to expand.”

The scientists’ model shows that Earth was periodically covered by glaciers, but the geologic evidence suggests that it was much warmer than that.  The calculations show that an atmosphere that contained 6% carbon dioxide would have kept the temperature high enough for life to thrive, but the soil samples show that the carbon dioxide concentration was not that high. So what’s the warming mechanism?  Eric Wolf and Brain Toon are still searching for it.

Since the 3-D model takes so much computing time (up to three months for a single calculation), we’ll be waiting a while for the answer.

“The ultimate point of this study is to determine what Earth was like around the time that life arose and during the first half of the planet’s history,” said Toon. “It would have been shrouded by a reddish haze that would have been difficult to see through, and the ocean probably was a greenish color caused by dissolved iron in the oceans. It wasn’t a blue planet by any means.” By the end of the Archean Eon some 2.5 billion year ago, oxygen levels rose quickly, creating an explosion of new life on the planet, he said.

And along the way, better models of Earth’s climate will come out of this study, enhancing scientists’ ability to predict what Earth’s future might look like, and scientists will learn more about the conditions of early Earth, which could help in assessing the habitability potential of other planets.

Explore the interactions of greenhouse gases and ice sheets in the High-Adventure Science climate investigation, and explore the search for extraterrestrial life in the High-Adventure Science space investigation.

http://www.sciencedaily.com/releases/2011/12/111205140521.htm

The Great Antarctic Glaciation

December 14th, 2011 by Sarah Pryputniewicz

About 33 million years ago, the Earth abruptly went from being warm and wet to having Antarctic ice cover.  Only 23 million years after the Paleocene-Eocene Thermal Maximum, a time of some of the warmest temperatures on Earth, ice covered the surface.  What happened?

According to a recent study by scientists at Yale and Purdue universities, the carbon dioxide level dropped. Carbon dioxide is a greenhouse gas that is contributing to the increased global temperatures on Earth today.

The scientists pinpointed the threshold for low levels of carbon dioxide below which an ice sheet forms at the South Pole. Matthew Huber, a professor of earth and atmospheric sciences at Purdue, said roughly a 40 percent decrease in carbon dioxide occurred prior to and during the rapid formation of a mile-thick ice sheet over the Antarctic approximately 34 million years ago.

“The evidence falls in line with what we would expect if carbon dioxide is the main dial that governs global climate; if we crank it up or down there are dramatic changes,” Huber said. “We went from a warm world without ice to a cooler world with an ice sheet overnight, in geologic terms, because of fluctuations in carbon dioxide levels.”

Having an ice-covered South Pole appears to be the tipping point for cooling the rest of the planet.  The team found that the threshold level of carbon dioxide necessary for ice formation is about 600 parts per million.  For reference, today’s carbon dioxide level is approximately 390 parts per million.  This is why ice sheets still remain on Earth today.

With carbon dioxide levels forecast to rise to 550-1,000 parts per million in the next 100 years, when will the ice sheets completely melt away?  Because the melting of an ice sheet is different than starting an ice sheet, and because the process is not linear, scientists can’t say for sure.  But it’s clear that once the carbon dioxide levels rise high enough, the Earth will have reached a tipping point in the warming direction and the ice sheets will melt away.

Huber next plans to investigate the impact of an ice sheet on climate.

“It seems that the polar ice sheet shaped our modern climate, but we don’t have much hard data on the specifics of how,” he said. “It is important to know by how much it cools the planet and how much warmer the planet would get without an ice sheet.”

So how warm will Earth be in the future?  What’s the cooling impact of the ice?  Will greenhouse gases continue to rise?  Will increased cloud cover compensate for the lack of ice?

Explore how greenhouse gases and ice affect Earth’s temperature and learn more about feedback and tipping points in the High-Adventure Science climate investigation.

http://www.sciencedaily.com/releases/2011/12/111201174225.htm

When in Drought…

December 12th, 2011 by Sarah Pryputniewicz

New groundwater and soil moisture drought indicator maps produced by NASA are available on the National Drought Mitigation Center’s website. They currently show unusually low groundwater storage levels in Texas. The maps use an 11-division scale, with blues showing wetter-than-normal conditions and a yellow-to-red spectrum showing drier-than-normal conditions. (Credit: NASA/National Drought Mitigation Center)

GRACE groundwater map of continental U.S.

The map (above) shows the change in stored groundwater in the contiguous United States.  Texas, which experienced record heat and wildfires this summer, is experiencing a very severe drought.  The change in stored water should not be a surprise given the weather conditions of the past year.  (By contrast, New England has a surplus of water from a very wet summer and the remnants of Hurricane Irene.)

Drought maps offer farmers, ranchers, water resource managers and even individual homeowners a tool to monitor the health of critical groundwater resources. “People rely on groundwater for irrigation, for domestic water supply, and for industrial uses, but there’s little information available on regional to national scales on groundwater storage variability and how that has responded to a drought,” Matt Rodell, a hydrologist at NASA’s Goddard Space Flight Center, said. “Over a long-term dry period there will be an effect on groundwater storage and groundwater levels. It’s going to drop quite a bit, people’s wells could dry out, and it takes time to recover.”

The question is: how long will it take to replenish the water that has been removed from the aquifers in Texas? Matt Rodell estimates, “Texas groundwater will take months or longer to recharge.  Even if we have a major rainfall event, most of the water runs off. It takes a longer period of sustained greater-than-average precipitation to recharge aquifers significantly.”

Water is a resource that everyone needs.  In dry environments, such as southwestern Texas, water is especially precious.  Water is used for the usual personal purposes, for agricultural purposes, and in natural gas wells.  For example, accessing the natural gas in the Eagle Ford shale deposit, which runs from the Mexican border towards Houston and Austin, requires millions of gallons of water to fracture the shale and release the stored hydrocarbons.

The prolonged Texas drought is putting more pressure on local officials about how best to use the limited amount of groundwater.  What is the best way to use the water supply?  Who gets first dibs?  How much should different businesses pay for water?  These are highly-important questions that can only be answered with a full understanding of how groundwater works.

You can explore how groundwater flows and propose solutions to water-supply issues in the High-Adventure Science water investigation.

http://www.nasa.gov/topics/earth/features/tx-drought.html

Drought spurring fracking concerns

Oil’s Growing Thirst for Water

Texas

More planets!

December 9th, 2011 by Sarah Pryputniewicz

A team of astronomers led by scientists at the California Institute of Technology have found 18 planets orbiting stars more massive than our Sun.  Finding planets is becoming more and more routine with the Kepler telescope, but these planetary discoveries help to answer questions about planetary formation–and raise other questions about planetary orbits.

The scientists focused on stars more than 1.5 times more massive than our Sun.  To look for planets, they used the “wobble” method, which looks for shifts in the apparent wavelengths coming from the star.  The 18 planets that they found are all larger than Jupiter.

According to John Johnson, assistant professor of astronomy at Caltech, these discoveries support a theory of planet formation. There are two competing explanations for how planets form: a) tiny particles clump together to make a planet and b) large amounts of gas and dust spontaneously collapse into big dense clumps that become planets.

The discovery of these planets supports the first explanation.

If this is the true sequence of events, the characteristics of the resulting planetary system — such as the number and size of the planets, or their orbital shapes — will depend on the mass of the star. For instance, a more massive star would mean a bigger disk, which in turn would mean more material to produce a greater number of giant planets.

So far, as the number of discovered planets has grown, astronomers are finding that stellar mass does seem to be important in determining the prevalence of giant planets. The newly discovered planets further support this pattern — and are therefore consistent with the first theory, the one stating that planets are born from seed particles.

The larger the star, the larger the planets that orbit it.

“It’s nice to see all these converging lines of evidence pointing toward one class of formation mechanisms,” Johnson says.

But there’s another mystery that’s come out of this discovery.  The orbits of these 18 newly-discovered large planets are mainly circular.  Planets around other Sun-like stars have circular and elliptical orbits.  Is there something about the larger stars that make it more likely  that planets will have a circular orbit?  Or is it just a phenomenon noticed because of the small sample size? Johnson says he’s now trying to find an explanation.

Stay tuned–not only may we find a planet that could harbor life, we could also learn something about the origin of our own solar system!

Learn more about finding planets and the search for extraterrestrial life in the High-Adventure Science investigation, Is there life in space?

http://www.sciencedaily.com/releases/2011/12/111202155801.htm

What caused the Paleocene-Eocene Thermal Maximum?

December 7th, 2011 by Sarah Pryputniewicz

What caused the Paleocene-Eocene Thermal Maximum (PETM)?

About 56 million years ago, Earth’s temperature was a lot warmer than it is today–as much as 21°F higher than today (see the graph).  Earth’s temperature is rising today, likely because of human emissions of greenhouse gases.  But 56 million years ago, there were no human emissions; there were no humans.  What caused the big increase in Earth’s temperature?  And could it happen again today?

Researchers at Rice University suggest that the temperature increase could well be due to releases of stored methane from the oceans.

Methane is a powerful greenhouse gas and a natural product of bacterial decomposition.  In the oceans, methane sinks into the sediments and freezes into a slushy gas hydrate, stabilized in a narrow band under the seafloor.

According to calculations done by the Rice University scientists, the warmer oceans resulted in more methane hydrate being stored.  At warmer temperatures, bacteria decompose organic materials faster, resulting in more methane in a shorter period of time.  They estimate that, just before the PETM, there was as much methane hydrate stored as there is today, in a smaller band than exists today.

If this band is disturbed, as by a meteor impact or earthquake, the methane can be rapidly released into the atmosphere.  More greenhouse gases in the atmosphere result in increased warming.  But there’s no evidence of there having been an impact.  So what happened to release the methane 56 million years ago?

Nobody really knows, but the significance is clear.

“I’ve always thought of (the hydrate layer) as being like a capacitor in a circuit. It charges slowly and can release fast — and warming is the trigger. It’s possible that’s happening right now,” said Gerald Dickens, a Rice professor of Earth science and an author of the study.

That makes it important to understand what occurred in the PETM, he said. “The amount of carbon released then is on the magnitude of what humans will add to the cycle by the end of, say, 2500. Compared to the geological timescale, that’s almost instant.”

“We run the risk of reproducing that big carbon-discharge event, but faster, by burning fossil fuel, and it may be severe if hydrate dissociation is triggered again,” Guangsheng Gu, lead author of the study, said, adding that methane hydrate also offers the potential to become a valuable source of clean energy, as burning methane emits much less carbon dioxide than other fossil fuels.

Learn more about the feedback loops involved in climate change in the High-Adventure Science climate investigation.

http://www.sciencedaily.com/releases/2011/11/111109111542.htm