Ian Edmonds - Academia.edu (original) (raw)

Papers by Ian Edmonds

This paper assesses and compares the performances of two daylight collection strategies, one pass... more This paper assesses and compares the performances of two daylight collection strategies, one passive and one active, for large-scale mirrored light pipes (MLP) illuminating deep plan buildings. Both strategies use laser cut panels (LCP) as the main component of the collection system. The passive system comprises LCPs in pyramid form, whereas the active system uses a tiled LCP on a simple rotation mechanism that rotates 360° in 24 hours. Performance is assessed using scale model testing under sunny sky conditions and ...

Solar Energy, 2004

The micro-light guiding shade is a device that acts to both shade the fac ßade from direct sunlig... more The micro-light guiding shade is a device that acts to both shade the fac ßade from direct sunlight and distribute daylight deep into subtropical buildings. The device was created in response to the need for daylighting technologies that can utilise direct sunlight while maintaining visual and thermal comfort in subtropical buildings. The created device has the form of a fixed panel with similar thickness and outward appearance as existing shades, yet performs the dual purposes of shading and light redirection. Experiments and computer lighting simulations were performed to assess the device's performance in terms of effectiveness, efficiency, implementation, cost and construction issues. Experimental results show that the device provides favourable illumination deep within a room, while reducing glare for room occupants. Computer simulations compare favourably with experimental measurements, and have been used to find the optimal configuration of the panels in various situations. Installation of the device on high rise commercial buildings will reduce reliance on artificial lighting while improving the visual performance of office workers.

Solar Energy Materials and Solar Cells, Feb 1, 1993

The manufacture, application and performance of a material which combines light deflecting proper... more The manufacture, application and performance of a material which combines light deflecting properties with good viewing transparency is described. The material, of similar thickness to conventional glass glazing, is produced by laminating laser cut acrylic sheet between sheets of glass. It is designed to replace glass in in clerestory windows and atria to improve the distribution of daylight in rooms. Equations for the deflection angle and amount of light deflected are derived and related to applications of the material for daylighting and for sunlight exclusion. Measured performance of the material in the daylighting application is obtained, in model rooms, for a wide range of sky conditions. The material is most effective as a hung or tilted window in direct sunlight, however improvement in interior illumination with the window vertical and in overcast conditions is also significant.

Solar Energy, Aug 1, 2002

Traditional adaptations of tropical / sub tropical buildings to high ambient irradiance from high... more Traditional adaptations of tropical / sub tropical buildings to high ambient irradiance from high elevations are outlined. Generally, these adaptations result in severe shading of window apertures, greatly reducing access to daylight. Some examples of optical systems designed to improve daylighting in tropical buildings are discussed. These include angle selective glazing, light guiding shades, vertical and horizontal light pipes, switchable glazing and angle selective skylights. The simulation of these devices within packages such as RADIANCE is also discussed.

Indoor and Built Environment, Aug 2, 2011

In Hong Kong, many buildings are high-rise blocks constructed close to each other resulting in se... more In Hong Kong, many buildings are high-rise blocks constructed close to each other resulting in severe sky obstructions, more particularly for rooms at the lower floors. Innovative daylighting technologies that transport natural light from outside towards the inner part of deep plan rooms are appropriate devices to improve daylight uniformity and visual comfort. Good visual effects and less lighting energy use may result if proper designs are employed. This paper studies the performance of light redirection systems via scale model under real sky conditions. The results demonstrate that laser cut panels can generally increase the interior daylight in the rear of the scale model room, improve the daylight uniformity and have the potential to reduce the electric lighting energy use.

Lighting Research & Technology, Mar 1, 1995

The daylighting of small interior rooms via skylight and vertical light pipe may be enhanced by d... more The daylighting of small interior rooms via skylight and vertical light pipe may be enhanced by deflecting low-elevation light more directly through the light pipe using laser-cut light deflecting panels. Theoretical expressions for light transmission versus elevation through simple ...

Utilising daylighting systems to redirect sunlight to illuminate the core of buildings is effecti... more Utilising daylighting systems to redirect sunlight to illuminate the core of buildings is effective in reducing Greenhouse emissions. This paper describes a daylighting system, developed for Australian conditions, known as Channel Panel. A graphical method for predicting the performance of Channel Panel in buildings is described. The method is illustrated by application to the design and costing of daylighting for a building in Brisbane. The graphical prediction is compared with measured daylighting performance in a scale model. The performance of the daylighting system in the building is discussed with respect to Greenhouse gas emission savings.

arXiv (Cornell University), Jan 13, 2014

We show that there is a previously unreported quad-annual variation in the~13.5 day component of ... more We show that there is a previously unreported quad-annual variation in the~13.5 day component of the aa index of geomagnetic activity. We derive a model based on the planetary tidal effect at the solar surface due to Mercury and Jupiter that, when combined with an equinoctial response of the magnetosphere, predicts the times of occurrence of predominantly quad-annual variation or predominantly semi-annual variation in the~13.5 day component of the aa index. In support of the model we show that, during years when the quad-annual variation in the~13.5 day component of aa index is predominant there is a large component at the 88 day periodicity of Mercury in the~13.5 day component of solar wind speed. As further support for the model we establish that significant peaks in the aa index spectrum are due to an 88 day modulation of 27 day period solar activity. The model also predicts the occurrence of planetary tidal effect maximum in anti-phase with solar cycle maximums around 1970 and we show this is consistent with prior observations of higher solar emissions during the 1975 solar cycle minimum than in the following solar cycle maximum. This effect offers a possible explanation of the reduced solar cycle maximums around 1970 and during the Dalton Minimum.

Several new algorithms have been developed for the RADIANCE lighting simulation program to better... more Several new algorithms have been developed for the RADIANCE lighting simulation program to better simulate new daylighting devices. Developments include algorithms to accurately simulate two new daylight redirecting devices. Measurement of devices' luminous outputs, sensitivity studies and improved sky models were also developed. Further investigations focussed on more accurate material modelling, and validation assessment techniques. Each algorithm has been applied to many simulation studies, improving simulation performance when compared with measurements and expectation. Thus, the developments outlined in this paper have improved the capability of RADIANCE to accurately assess the contributions of new daylighting devices to improved building performance. Following descriptions of the developed algorithms, the method of implementation in a typical RADIANCE simulation is discussed.

arXiv (Cornell University), Jan 29, 2023

This paper describes a reciprocating balloon engine that operates over a height range of several ... more This paper describes a reciprocating balloon engine that operates over a height range of several kilometres. The theory of the engine is outlined and used to show that engines based on the largest commercial hot air balloons can generate average power outputs of 50 kW with 7% thermal efficiency. Estimated installation cost to power output ratio is similar to that of other renewable energy technologies.

arXiv: Solar and Stellar Astrophysics, 2015

There have been numerous reports of quasiperiodicities in solar activity in the intermediate peri... more There have been numerous reports of quasiperiodicities in solar activity in the intermediate period range. However, no accepted explanation for the episodic occurrence of quasiperiodicities has emerged. This paper examines the possibility that the periodicities are associated with a Mercury Sun interaction of base period 88 days. To test this idea we band pass filter the 140 year long daily sunspot area data to obtain the 88 day period and 176 day sub harmonic period components of the data and compare the time variation of the components with the time variation of the orbital radius of Mercury, or more specifically with the time variation of the tidal effect of Mercury. We were able to show that, when successive episodes of the occurrence of the 88 day period component were discrete and not overlapping in time, the time variation of this component of sunspot area was either exactly in-phase or exactly in anti-phase with the time variation of tidal effect. A similar result was obtain...

Cornell University - arXiv, Oct 24, 2021

Solar quasi-biennial oscillations, (QBOs), with period range 0.6-4 years, are prominent in record... more Solar quasi-biennial oscillations, (QBOs), with period range 0.6-4 years, are prominent in records of solar activity. Here we show that the 1.6 year QBO in solar activity has the exceptional feature of phase inversion between each solar cycle in the sequence of four solar cycles, 20 to 23. The hypothesis advanced is that this feature is due to synchronicity between solar activity and planetary alignment. An index of alignment between Earth and Mercury, Venus, Jupiter and Saturn is shown to have dominant peaks of alignment separated by 1.6 years in each solar cycle with, however, peak alignments shifting by half a period, 0.8 years, between alternate solar cycles. Accepting that solar activity increases when planets align would explain the phase inversion in alternate solar cycles observed in the 1.6 year QBO. Two new methods were developed to test this hypothesis: (a) Narrow band filtering of solar activity with the pass band based on the frequency content of the planetary alignment index. (b) Superposing intervals of raw solar activity data centred on times of maximum planet alignment. Both methods provided strong support for the hypothesis. Planetary alignment is complex but predictable enabling the forecasting of solar QBO intermittency and future QBO spectral content. Highlights  1.6 year QBO in solar activity reverses phase between solar cycles  Evidence of increased solar activity when close planetary alignment occurs  Superposed raw solar activity data correlates with a planetary alignment index  Prediction of QBO intermittency based on mode change in planet alignment indices  Forecast of QBO spectral content in solar cycles 25 and 26 Keywords: Solar quasi-biennial oscillations; planetary alignments; forecasting intermittency; predicting solar activity; galactic cosmic rays; F10.7 cm radio flux 1990). These shorter term periodicities are generally known as Rieger periodicities. Later, mid-term periodicities were discovered in the period range 1 to 3 years, now referred to as quasi-biennial oscillations (QBOs), (Rouilliard and Lockwood 2004, Vecchio et al 2012). Subsequently, many studies, as reviewed by Bazilevskaya et al (2014), have been concerned with QBOs. The studies of QBOs fall into three categories: Studies that report the presence or re-emergence of specific QBO in each succeeding solar cycle, e.g. (Chowdhury and Kudela 2018, Maghrabi et al 2020); studies of the relationship between solar variables associated with a specific QBO, e.g. Rouilliard and Lockwood's (2004) study of the relationship between QBO of open solar magnetic flux and cosmic rays at 1.68 year period, and studies searching for the origin of the QBOs, e.g. Wang and Sheeley's (1995) assessment that QBOs derive from random variation of the Sun's large scale magnetic field, the Gurgenashvili et al (2016), Gachechiladze et al (2019), Zaqarashvili et al (2010), and Zaqarashvili et al (2021) assessments that QBOs are related to unstable magnetic Rossby waves in the solar tacholine, the Beaudoin et al (2016) simulation of QBOs associated with a secondary dynamo process operating in the solar convection zone, Scaffeta and Willson's (2013) evidence that the ~1.09 year periodicity in total solar irradiance is associated with Earth-Jupiter planetary alignments, and the Cionco et al (2021) assessment that periodicity in quantities like solar irradiance and F10.7 cm radio flux may be due to planetary induced variations in the Earth-Sun distance. The last category of study, the physical mechanism inducing the periodicities, is contradictory with some of the proposed mechanisms briefly reviewed by Bazilevskaya et al (2014). Interest in a planetary connection to oscillations in solar activity dates from the suggestion by Wolf (1859) that the ~decadal periodic variation in solar activity may be linked to the motion of Jupiter and Saturn. However, evidence supporting influence of planetary alignments on solar activity via a tidal influence, Scafetta (2013), or by planet torques on a non spherical tacholine, Abreu et al (2012), or by spin orbit coupling, Wilson (2013), is not mentioned in the Bazilevskaya et al (2014) review, possibly due to the planetary effect being assessed as too small, Callebaut et al (2012), or the correlations between solar activity cycles and planetary alignments assessed as statistically insignificant, Cameron and Schussler (2013), Poluianov and Usoskin (2014). However, Charbonneau (2013), suggested that sunspot-forming magnetic field concentrations, as described by Fisher et al (2000), may be subject to thresholds that could be susceptible to small planet-induced variations leading to the periodic emergence of sunspots at periods associated with planetary motions, a view supported Stefani et al (2019). Charbonneau (2013) points out that while such an effect seems unlikely, the effect, if proven, would provide a basis for forecasting (and backcasting) of solar activity. This paper is not concerned with the physical mechanism causing quasi-periodic variations in solar activity but tests the hypothesis that solar activity in the QBO period range is synchronous with planet alignments. Testing if solar activity is synchronous with planet alignment has a long and somewhat contentious history, (

International Journal of Astronomy and Astrophysics

The Sun would be subject to a significant variation of orbital motion about the solar system bary... more The Sun would be subject to a significant variation of orbital motion about the solar system barycentre if a small planet is orbiting at a very large distance. This paper assesses if the Planet 9 hypothesis, the existence of a ninth planet, is consistent with the planetary hypothesis: the synchronisation of sunspot emergence to solar inertial motion (SIM) induced by the planets. We show that SIM would be profoundly affected if Planet 9 exists and that the hypothesised effect of SIM on sunspot emergence would be radically different from the effect of SIM due to the existing eight planets. We compare the frequency and time variation of Sun to barycentre distance, R B , calculated for both the eight and nine planet systems, with the frequency and time variation of sunspot number (SSN). We show that including Planet 9 improves the coherence between R B and SSN in the decadal, centennial and millennial time range. Additionally, as the variation of R B is sensitive to the longitude and period of Planet 9, it is possible to adjust both parameters to fit the variation of R B to the SSN record and obtain new estimates of the period and present longitude of Planet 9. Finally, we develop the hypothesis that planetary induced solar acceleration reduces meridional flow and consequently sunspot emergence thereby providing an explanation for the observed coincidence of grand solar minima with intervals of extreme solar acceleration.

Australian Journal of Multi-Disciplinary Engineering

arXiv: Solar and Stellar Astrophysics, 2016

In this paper we examine the possibility that intermediate range periodicities in sunspot area ca... more In this paper we examine the possibility that intermediate range periodicities in sunspot area can be linked to Mercury or to Mercury-planet conjunction periods. We show that peaks at the 45 day Mercury-Jupiter conjunction period, the 116 day first harmonic period of the Mercury-Earth conjunction and the 289 day period of the sub harmonic Mercury-Venus/Mercury-Earth conjunctions are prominent in spectra of sunspot area. We observe two prominent peaks close to the 88 day Mercury periodicity and two prominent peaks close to the 176 day first sub harmonic of Mercury periodicity. To confirm that the peaks arise as sidebands we band pass filter the sunspot area record to isolate the 88 and 176 day components of sunspot area. The components occur in episodes of duration from 1.5 to 4 years, with successive episodes usually overlapping in time but, for significant intervals in the record, the episodes were discrete, i.e. not overlapping. The time variation of the components was compared wi...